010506   Zarrinkhameh M;Zendehnam A;Hosseini S M; Robatmili N;Arabzadegan M (Thin Film Laboratory, Physics Dep, Faculty of Science, Arak University, Arak-38156-8-8349, Iran, Email: zarrinkhameh55@yahoo.com) : Effect of oxidation and annealing temperature on optical and structural properties of SnO₂. Bull Mater Sci 2014, 37(3), 533-9.

Tin oxide thin films were deposited on glass substrate with 100 nm thickness of Sn, which was coated by magnetron sputtering followed by thermal oxidation at different temperatures. The effect of oxidation temperature on the optical and structural properties of SnO₂ films were investigated. Higher transmittance, lower absorption and lesser structural defects were obtained at higher temperatures. Optical bandgap increases with temperature, while the Urbach energy showed reduction. The X-ray diffraction studies showed that at lower temperatures (300, 350°C), a combined phase of SnO and SnO₂ was obtained, while at higher temperatures (400, 450°C), a nearly polycrystalline SnO₂ film with preferred orientation of (101) was produced. Annealing of the samples at 500-650°C caused the transmittance and optical bandgap increased, while the absorption decreased. Reduction of the Urbach energy after annealing could be attributed to the reduction of the degree of thermal disorder. AFM studies showed that although the thin films were annealed under similar condition, their roughness was not similar because of different oxidation temperatures, which means that initial oxidation temperature played an important role on surface uniformity of SnO2 thin films.

9 illus, 31 ref

010505   Zahedi F;Dariani R S;Rozati S M (Physics Dep, Alzahra University, Tehran 1993893973, Iran, Email: dariani@alzahra.ac.ir) : Structural, optical and electrical properties of ZnO thin films prepared by spray pyrolysis: effect of precursor concentration. Bull Mater Sci 2014, 37(3), 433-9.

ZnO thin films have been prepared using zinc acetate precursor by spray pyrolytic decomposition of zinc acetate on glass substrates at 450°C. Effect of precursor concentration on structural and optical properties has been investigated. ZnO films are polycrystalline with (002) plane as preferential orientation. The optical transmission spectrum shows that transmission increases with decrease in the concentration and the maximum transmission in visible region is about 95% for ZnO films prepared with 0.1 M. The direct bandgap value decreases from 3.37 to 3.19 eV, when the precursor concentration increases from 0.1 to 0.4 M. Photoluminescence spectra at room temperature show an ultraviolet (UV) emission at 3.26 eV and two visible emissions at 2.82 and 2.38 eV. Lowest resistivity is obtained at 2.09 Ω cm for 0.3 M. The current- voltage characteristic of the ZnO thin films were measured in dark and under UV illumination. The values of photocurrent and photoresponsivity at 5 V are increased with increase in precursor concentration and reaches to maximum value of 1148 μA and 0.287 A/W, respectively which is correlated to structural properties of ZnO thin films.

6 illus, 3 tables, 45 ref

010504   Yuce E (NO, Pamukkale University, Electrical and Electronics Engineering Dep, 20070 Kinikli-Denizli, Turkey, Email: erkanyuce@yahoo.com ) : Novel instrumentation amplifier and integrator circuits using single DDCC and only grounded passive elements. Indian J pure appl Phys 2014, 52(11), 767-75.

In the present paper, very simple voltage-mode instrumentation amplifier (IA) and integrator structures including only grounded passive components yielding easy integration are proposed. The proposed IA and integrator use single differential difference current conveyor. The proposed IA without requiring critical passive component matching conditions can be constructed with only two small-valued resistors to obtain high gain. The proposed integrator circuit has the feature of improved low frequency performance, which can be accomplished via a resistive component matching constraint. Also, both of the proposed circuits have high input impedances yielding easy cascadability. Both of the proposed configurations consume less power, and can be operated at higher frequencies. Some simulation and experimental results are included to confirm the theory.

13 illus, 3 tables, 33 ref

010503   Yu K;Chen T;Wang X;Zhang C (School of Mechanical Engineering & State Key Laboratory for Strength a, Xi'an Jiaotong Univ, Xi'an 710049, China, Email: tnchen229@126.com) : Band gap properties in two-dimensional phononic crystal slabs with neck structures. Indian J pure appl Phys 2014, 52(8), 525-30.

The numerical investigation on elastic wave band gap properties in two-dimensional phononic crystal slabs composed of periodic cylinders inserted in a homogeneous slab is presented. The cylinders are not connected with the slab directly but linked it through some neck structures constituted by part of an annular cylinder. By using the finite element method, the band structures of the phononic crystal are analyzed and the geometric parameters of the structure are studied for their effects on the band gap properties. Results show that band gaps with low frequencies appear in this structure. The largest band gap can be influenced significantly by the geometric parameters of the neck (including the length, the position, the central angle and the rotation angle of the neck). Furthermore, the vibration eigenmodes of the structure are calculated to reveal the relationship between band gaps and the geometry of the structure. Results show that the occurrence of low frequency band gaps are attributed to the coupling effect of swing modes of cylinders and the plate wave modes of the slab matrix.

7 illus, 30 ref

010502   Yisif Pandir (Mathematics Dep, Faculty of Science and Arts, Bozok University, 66100 Yozgat, Turkey, Email: yusuf.pandir@bozok.edu.tr) : New exact solutions of the generalized Zakharov-Kuznetsov modified equal-width equation. Pramana J Phys 2014, 82(6), 949-64.

In this paper, new exact solutions, including soliton, rational and elliptic integral function solutions, for the generalized Zakharov-Kuznetsov modified equal-width equation are obtained using a new approach called the extended trial equation method. In this discussion, a new version of the trial equation method for the generalized nonlinear partial differential equations is offered.

22 ref

010501   Wang L;Qin X Y (Ley Laboratory of Materials Physics, Institute of Solid State Physics, Hinese Academy of Sciences, 230031 Hefei, P.R. China, Email: wanglin1172@126.com) : Effect of calcination methods on electrochemical performance of NiO used as electrode materials for supercapacitor. Bull Mater Sci 2014, 37(3), 649-54.

Ni(OH)₂ precursors were prepared via the precipitation transformation method, which was originated from Na₂C₂O₄, NiSO_4.6H₂O and urea. NiO samples were successfully obtained by calcining Ni(OH)₂ precursor with different calcination methods. Some were calcination in a tube furnace under the nitrogen flow and others were calcination in a muffle furnace. The products were well-characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The influence of calcination methods on electrochemical performance of NiO samples were investigated. Moreover, the possible reason was proposed. The charge storage mechanism of NiO positive electrode in aqueous electrolyte was discussed. The electrochemical test showed that the as-prepared NiO prepared in a tube furnace can exhibit a good pseudocapacitance behaviour due to the higher utilization of active material.

8 illus, 1 table, 18 ref

010500   Vinod Kumar;Pukazhselvan D;Tyagi A K;Singh S K (Physics Dep, Deenbandhu Chhotu Ram University of Science and Technology, Murthal-131 039) : Hydrogen absorption/desorption characteristics of room temperature ZrMn_2-x Ni_x system (x = 1.25-1.50). Bull Mater Sci 2014, 37(3), 655-60.

Deals with the hydrogen storage characteristics of C15 laves phase ZrMn_2-x Ni_x system tailored within the x values of 1.25 to 1.50. Drastic variations in thermodynamics of the hydride phase is observed for any little changes of concentration x within this narrow range. The most promising room temperature hydrogen storage materials are found to be formed within the range of 1.35 to 1.45 where ~ 2.5 to 2.9 H/F.U. can be reversibly stored under the ideal operating conditions. The heat of the reaction is found to be ~ 17 kJ/mol, which means these are promising candidates for stationary and short range mobile applications. The phase structural features and the thermodynamic aspects of all the materials are discussed in detail.

7 illus, 3 tables, 27 ref

010499   Ullah M;Ejaz Ahmed;Abdelbary Elhissi;Waqar Ahmed (Physics Dep, Bahauddin Zakariya University, Multan, Pakistan, Email: prof.w.ahmed@gmail.com) : Low resistance polycrystalline diamond thin films deposited by hot filament chemical vapour deposition. Bull Mater Sci 2014, 37(3), 579-83.

Polycrystalline diamond thin films with outgrowing diamond (OGD) grains were deposited onto silicon wafers using a hydrocarbon gas (CH₄) highly diluted with H₂ at low pressure in a hot filament chemical vapour deposition (HFCVD) reactor with a range of gas flow rates. X-ray diffraction (XRD) and SEM showed polycrystalline diamond structure with a random orientation. Polycrystalline diamond films with various textures were grown and (111) facets were dominant with sharp grain boundaries. Outgrowth was observed in flowerish character at high gas flow rates. Isolated single crystals with little openings appeared at various stages at low gas flow rates. Thus, changing gas flow rates had a beneficial influence on the grain size, growth rate and electrical resistivity. CVD diamond films gave an excellent performance for medium film thickness with relatively low electrical resistivity and making them potentially useful in many industrial applications.

4 illus, 25 ref

010498   Tripathi A;Shukla R K (Physics Dep, University of Lucknow, Lucknow-226 007, Email: rajeshkumarshukla_100@yahoo.co.in) : Structural, Optical and Photoluminescence Study of Nanocrystalline SnO₂ Thin Films Deposited by Spray Pyrolysis. Bull Mater Sci 2014, 37(3), 417-23.

Undoped SnO₂ thin films prepared by spray pyrolysis method reveal polycrystalline nature with prominent peaks along (110), (101) and (211) planes. All the films are nanocrystalline with particle size lying in the range of 3.14-8.6 nm calculated by DS formula. Orientation along plane (200) decreases continuously as molar concentration of SnO₂ increases. Dislocation density along plane (110) also decreases as molar concentration increases except 0.4 M SnO₂ thin film. Scanning electron microscopy image of the films contain jelly structures along with agglomerated clusters of particles. SnO₂ synthesized successfully, which confirms by Fourier transform infra-red spectroscopy. The optical transmittance spectra of 0.2 M SnO₂ thin film shows transmittance about 50-60% transmission in visible and near infrared region with a sharp cut off in the ultraviolet region. The transmission decreases in visible and near infrared region as molar concentration increases. Broad UV emission at 398 nm is observed in photoluminescence spectra of the films along with a blue emission, when excited at 250 nm wavelength. Emission intensity randomly changed as SnO₂ molar concentration increases. When excited at 320 nm, one UV and two visible peaks appeared at 385, 460 and 485 nm, respectively.

9 illus, 3 tables, 25 ref

010497   Srivastava A K;Baboo V;Narayana B;Sarojini B K;Misra N (Physics Dep, Lucknow Univ, Lucknow-226 007, Email: neerajmisra11@gmail.com) : Comparative DFT study on reactivity, acidity and vibrational spectra of halogen substituted phenylacetic acids. Indian J pure appl Phys 2014, 52(8), 507-19.

A detailed first principle study on the three halogenated phenylacetic acid i.e. 2-(2-halophenyl)acetic acid where -halo=fluoro/chloro/bromo has been carried out. The calculated structural properties show close resemblance with the crystallographic data. The reactivity of molecules using various descriptors -local such as fukui functions, local softness and electrophilicity as well as -global i.e. electronegativity, hardness, HOMO-LUMO gap etc. along with acidity of the same are calculated and discussed. The vibrational spectra of chloro-and bromo-substituted molecules are calculated and compared with those obtained with experimental FTIR method while that of fluoro-substituted is predicted theoretically.

3 illus, 5 tables, 33 ref

010496   Singh S;Singh M;Kotnala R K;Verma K C (Akal School of Chemistry, Eternal Univ, Baru Sahib, Himachal Pradesh-173 101, Email: dkuldep.physics@gmail.com) : Hydrothermal synthesis of NiFe₂O₄, Ni_0.6Zn_0.4Fe₂O₄ and Ni_0.6Zn_0.4Fe₂O₄/SrFe₂O ₄: nanostructure, magnetic and dielectric properties. Indian J pure appl Phys 2014, 52(8), 550-5.

NiFe₂O₄ (NF), Ni_0.6Zn_0.4Fe₂O₄ (NZF) and Ni_0.6Zn_0.4Fe₂O₄/SrFe₂O₄ (NZF/SF) nanostructures were prepared by hydrothermal synthesis at 180°C/48 h. The synthesis of NF shows nanoparticles of average size 19 nm. However, NZF and NZF/SF show nanowires of average diameter <126>23 and 6 nm, and length 325 and 160 nm, respectively. A growth mechanism for fabrication of nanostructure is given. The X-ray diffraction pattern confirms the polycrystalline structure of spinel phase of NF and NZF and orthorhombic phase of SF ferrite. The microstructural analysis is confirmed by transmission electron microscopy. The ferromagnetic behaviour of each ferrite sample is confirmed by M-H hysteresis. However, the M-H hysteresis of composite NZF/SF also shows spring like vibrations which indicate a strong coupling between hard and soft phases. The higher value of remanent magnetization is observed in NZF/SF which is possible by combining soft/hard ferrite phase. The effect of low dimensions of NZF/SF nanostructure is to control dielectric constant with low loss up to higher frequency of 120 MHz, has been observed.

7 illus, 1 table, 22 ref

010495   Singh D P;Gupta S K;Yadav S P;Sharma P K; Pandey A C;Manohar R (Liquid Crystal Research Lab, Physics Dep, University of Lucknow, Lucknow-226 007, Email: rajiv.manohar@gmail.com) : Guest-host interaction in ferroelectric liquid crystal-nanoparticle composite system. Bull Mater Sci 2014, 37(3), 511-18.

Deals with the characterization of a ferroelectric liquid crystal-nanoparticle (FLC-NP) composite system. The dielectric, electrical and polarization property of the FLC-NP composite system have been studied as a function of temperature and frequency. Ferroelectric Cu-doped ZnO (Cu-ZnO) nanoparticles have been added to the pure ferroelectric liquid crystal (FLC) Felix 17/100. The nanoparticles are bigger in size as compared to FLC molecules; therefore, they distort the existing geometry of FLC matrix and set up an antiparallel correlation with the dipole moments of the host FLC molecules. This antiparallel correlation of guest-host geometry reduces the net ferroelectricity of the composite system and modifies all the physical properties of the pure FLC. The change in properties has been analysed and explained in the light of guest-host interaction.

7 illus, 1 table, 25 ref

010494   Sarma J;Dev A N (Mathematics Dep, R G Baruah College, Guwahati-781 025, Email: apulnarayan@gmail.com) : Dust acoustic waves in warm dusty plasmas. Indian J pure appl Phys 2014, 52(11), 747-54.

The nonlinear propagation of dust acoustic waves in warm dusty plasma system containing Boltzmann distribution of electrons and ions, arbitrary charged dust grains has been investigated by employing the reductive perturbation technique (RPT). The nonlinear waves have been observed in the case of negative charged dust grains from the stationary solution of the Korteweg-de Vries (K-dV) equation, Burgers equation and Korteweg-de Vries-Burgers (KdV-Burgers) equation. The analytical solution of K-dV-Burgers and Burgers equation are numerically analyzed and DA shock waves propagation is reported. The critical values of the nonlinear coefficient A and the difference of shock wave profile of Burgers equation and K dV-Burgers equation for same parameters, have been observed.

6 illus, 2 tables, 24 ref

010493   Sanjay Kumar;Sharma S K;Pandey O P (NO, N.C. College of Engineering, Israna, Panipat-132 107, Email: sanjay2076@gmail.com) : Estimation of volume dependence of Gruneisen parameter for NaCl and ε-Fe. Indian J pure appl Phys 2014, 52(8), 541-4.

The present paper proposes a new empirical expression to evaluate the values of volume dependence of the Gruneisen parameter. NaCl and ε-Fe have been taken to check the reliability of the present expression. The results obtained reveal that the present model is reliable due to a reasonably good agreement between calculated values and the values of Gruneisen parameter derived from experimental data on thermoelastic properties.

3 illus, 3 tables, 28 ref

010492   Saddeek Y B;Gaafar M S (Physics Dep, Faculty of Science, Majmaa University, Zulfi, Saudi Arabia, Email: ysaddeek@gmail.com) : Rigidity of semiconducting vanadate glasses and its importance in use of coatings. Bull Mater Sci 2014, 37(3), 661-7.

Elastic moduli of some multicomponent vanadate based glasses were analysed in terms of the bond compression model by some physical parameters such as, the density, average stretching force constant and average atomic ring size. These parameters were calculated for all the glass series and for all the glass composition to estimate the rigidity of these glasses. The results showed that the average force constant and the elastic moduli of these glasses are sensitive to the decrease in PbO content. This behaviour was attributed to the increase in the molar volume and the role of different modifiers. These parameters along with the coordination number of the glasses affect the glass transition temperature. The correlation between the elastic moduli and thermal properties of these samples showed that 0.25MoO₃-0.25PbO-0.5V₂O₅ glass is the most rigid and has an applicable glass transition temperature for coating.

6 illus, 2 tables, 49 ref

010491   Rezaei B;Boroun G R (Physics Dep, Razi University, Kermanshah 67149, Iran, Email: grboroun@gmail.com) : Shadowing corrections to the derivative of the reduced cross-section at small χ. Pramana J Phys 2014, 82(6), 1031-8.

Analyse the derivative of the reduced cross-section ∂σ^{s_r/σlny <157>x, using the nonlinear Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (NLDGLAP) evolution equation at small x. The small x behaviour of the structure functions are obtained by solving the Gribov, Levin, Ryskin, Mueller and Qiu (GLR-MQ) evolution equation with the nonlinear shadowing term incorporated. We show that the strong rise corresponding to the linear QCD evolution equations, can be tamed by screening effects.}

1 illus, 2 tables, 24 ref

010490   Reham M;Shabaraa;Aly S H (Physics Dep, Faculty of Science, Damietta University, Egypt, Email: rehamph@hotmail.com) : Electric, magnetic, elastic and pressure-induced crystallographic phase transition properties of YbN using first-principle approach. Indian J pure appl Phys 2014, 52(11), 755-9.

The structural, magnetic and elastic properties of the rare earth nitride YbN under hydrostatic pressure have been investigated using the Full Potential Non-orthogonal Local-Orbital minimum basis method (FPLO) using the Local Spin Density Approximation (LSDA) and Generalized Gradient Approximation (GGA). Three phase transitions are predicted from rock-salt (RS) to CsCl, zinc-blend (ZB) to CsCl, and ZB to RS at 220, 12, and-15 GPa, respectively. The half-metallic property was found only in the ZB phase, while the RS and CsCl phases show a metallic behaviour. The bulk moduli of YbN in RS, CsCl and ZB structures are calculated to be 172.8, 160, and 115.3 GPa, respectively.

6illus, 2 tables, 24 ref

010489   Rambu A P;Iftimie N (Faculty of Physics, Alexandru Ioan Cuza University of Iasi, 11 Carol I Blvd, 700506 Iai, Romania, Email: alicia.rambu@uaic.ro) : Synthesis and characterization of thermally oxidized ZnO films. Bull Mater Sci 2014, 37(3), 441-8.

Metallic zinc thin films were deposited onto glass substrates using vacuum thermal evaporation method. By thermal oxidation of as-deposited Zn films, in ambient conditions, at different temperatures (570, 670 and 770 K, respectively, for 1 h) zinc oxide thin films were obtained. The structural characteristics of the obtained films were investigated by X-ray diffraction technique and atomic force microscopy. Characteristic XRD patterns of oxidized films show small and narrow peaks superimposed on the large broad background of the amorphous component of the substrate. Optical transmittance spectra were recorded and it was observed that the transmittances of the studied films increased with increasing oxidation temperature. The values of the optical bandgap, E_g evaluated from Tauc plots, were found to be ranged between 3.22 and 3.27 eV. Electrical conductivity measurements were performed and it was observed that, after performing a heat treatment, the electrical conductivity of analysed samples decreased with one or two orders of magnitude. The gas sensitivity was investigated for some reducing gases such as acetone, methane and liquefied petroleum gas and it was observed that the films studied were selective to acetone.

7 illus, 1 table, 28 ref

010488   Rajesh K R;Kannan V;Kim M R;Chae Y S;Rhee J K (Millimeter- Wave Innovation Technology Research Centre (MINT), Dongguk Univ, Seoul 100-715, Republic of Korea, Email: rajthinfilms@yahoo.co.in) : High mobility polymer gated organic field effect transistor using zinc phthalocyanine. Bull Mater Sci 2014, 37(1), 95-9.

Organic thin film transistors were fabricated using evaporated zinc phthalocyanine as the active layer. Parylene film prepared by chemical vapour deposition was used as the organic gate insulator. The annealing of the samples was performed at 120 °C for 3 h. At room temperature, these transistors exhibit p-type conductivity with field-effect mobilities ranging from 0.025-0.037 cm^{2/Vs and a (I_on/I_off) ratio of <126>103. The effect of annealing on transistor characteristics is discussed.}

7 illus, 23 ref

010487   Qasrawi A F;Abu-Zaid S F;Ghanameh S A;Gasanly N M (Physics Dep, Arab-American University, Jenin, West Bank, Palestine, Email: aqasrawi@atilim.edu.tr) : Dielectric and photo-dielectric properties of TlGaSeS crystalsm. Bull Mater Sci 2014, 37(3), 505-9.

Room temperature, dark and photo-dielectric properties of the novel crystals TlGaSeS are investigated in the frequency, intensity and biasing voltage having ranges of ~ 1-120 MHz, 14-40 klux and 0-1 V, respectively. The crystals are observed to exhibit a dark high frequency effective dielectric constant value of ~ 10.65 x 10^{3 with a quality factor of ~ 8.84 x 104 at ~ 120 MHz. The dielectric spectra showed sharp resonance- antiresonance peaks in the frequency range of ~ 25-250 kHz. When photoexcited, pronounced increase in the dielectric constant and in the quality factor values with increasing illumination intensity are observed. Signal amplification up to ~ 33% with improved signal quality up to ~ 29% is attainable via photoexcitation. On the other hand, the illuminated capacitance-voltage characteristics of the crystals reflected a downward shift in the voltage biasing and in the built-in voltage of the device that is associated with increase in the uncompensated carrier density. The increase in the dielectric constant with increasing illumination intensity is ascribed to the decrease in the crystal's resistance as a result of increased free carrier density. The light sensitivity of the crystals, the improved dielectric properties and the lower biasing voltage obtained via photoexcitation and the well-enhanced signal quality factor of the crystals make them promising candidates for optical communication systems.}

3 illus, 1 table, 17 ref

010486   Pushpalatha M;Srinivasu C;Narendra K (Physics Dep, Andhra Loyola College, Vijayawada, Andhra Pradesh) : Ultrasonic investigations on binary mixture of acetophenone with N-butanol at temperatures 303.15 K - 323.15 K. Int J Res Pharm Chem 2013, 3(1), 129-33.

Ultrasonic velocity, density and viscosity values are measured in a binary mixture of acetophenone with n-butanol at temperatures T = (303.15, 308.15, 313.15, 318.15 and 323.15) K over the entire mole fraction range. The experimental data is used to calculate various thermo acoustic parameters like Adiabatic compressibility (β), intermolecular free length (Lf), molar volume (V_m), free volume (V_f), internal pressure (π), enthalpy (H), acoustic impedance (Z), Rao's constant (R) and Wada's constant (w). The results are explained in the light of molecular interactions.

4 tables, 17 ref

010485   Pushpalatha H L;Bellappa S;Narayanaswamy T N; Ganesha R (Physics Dep, Yuvaraj's College, Mysore Univ, Mysore-570 005, Email: rajeshaganesha@gmail.com) : Structural and optical properties of CdS thin film obtained by chemical bath deposition and effect of annealing. Indian J pure appl Phys 2014, 52(8), 545-9.

Cadmium sulphide (CdS) thin film was deposited on glass substrate by chemical bath deposition (CBD) by single dip method. The bath-temperature was at 80°C and pH at 11. The film was annealed in air at 300°C for one hour. The as-deposited and annealed films were characterized by XRD, UV-visible spectrophotometer, EDAX and photoluminescence study. The film-thickness of 391.1 nm was revealed by Ellipsometry. Coexistence of hexagonal and cubic structure of the as-deposited film was confirmed by XRD. On annealing, the film was confirmed to be purely hexagonal. The band gaps of 2.35 eV of the as-deposited film and 2.29 eV of the annealed film were derived from the optical transmittance data of UV-VIS spectrum. Photoluminescence (PL) spectrum of the CdS thin film exhibits green and red emission peaks with different intensity on annealing. EDAX spectrum confirms the transformation of CdS thin film from off-stoichiometric to near stoichiometric state on annealing.

9 illus, 17 ref

010484   Patra P;Mandal T;Saha J P (Physics Dep, University of Kalyani, Kalyani-741 235, Email: monk.ju@gmail.com) : Quantum restoration of broken symmetry in one-dimensional loop space. Pramana J Phys 2014, 82(6), 965-71.

For one-dimensional loop space, a nonlinear nonlocal transformation of fields is given to make the action of the self-interacting quantum field to the free one. A specific type of classically broken symmetry is restored in quantum theory. One-dimensional sine-Gordon system and sech interactions are treated as the explicit examples.

14 ref

010483   Patil L A;Suryawanshi D N;Pathan I G;Patil D G (Nanomaterials Research Lab, Physics Dep, Pratap College, Amalner-425 401, Email: plalachand_phy_aml@yahoo.co.in) : Nanocrystalline Pt-doped TiO₂ thin films prepared by spray pyrolysis for hydrogen gas detection. Bull Mater Sci 2014, 37(3), 425-32.

Nanostructured pure and Pt-doped TiO2 thin films were prepared by chemical spray pyrolysis technique. Aqueous solution of TiCl₃.6H₂O (001 M) was chosen as the starting solution for the preparation of pure TiO2 thin film. Aqueous solutions of PtCl66H2O (001 M) and TiCl36H2O (001 M) were mixed in volume % of 1 : 99, 25 : 975 and 5 : 95 respectively to obtain Pt-doped TiO2 thin films. The solutions were sprayed onto quartz substrate heated at 350 øC temperature to obtain the films. These thin films were fired for one hour at 550 øC. The sensing performance of these films was tested for various gases such as LPG, H2, CO2, ethanol, NH3 and Cl2 (1000 ppm). The Pt-doped TiO2 (1 : 99) was observed to be most sensitive (572) to H2 at 400 øC with high selectivity against other gases. Its response time was short (10 s) and recovery was also fast (14 s). To understand the reasons behind the gas-sensing performance of the films, their structural and microstructral properties were studied using X-ray diffraction and electron microscopy (FE-SEM and TEM), respectively. Thicknesses of all these samples were determined using Surface Profiler. The results are interpreted.

12 illus, 4 tables, 47 ref

010482   Nikabadi H R;Shahtahmasebi N;Rokn-Abadi M R; Karimipour M;Bagheri Mohagheghi M M (Physics Dep, Ferdowsi University of Mashhad, Mashhad, Iran, Email: masoud.karimipour@gmail.com) : Structural verification and optical characterization of SiO₂-Au-Cu₂O nanoparticles. Bull Mater Sci 2014, 37(3), 527-32.

In this paper, SiO₂-Au-Cu₂O core/shell/shell nanoparticles were synthesized by reducing gold chloride on 3-amino-propyl-triethoxysilane molecules attached silica nanoparticle cores for several stages. Cu₂O nanoparticles were synthesized readily with the size of 4-5 nm using a simple route of sol-gel method Then, they were clung to the surface of Au seeds. The morphology of the resultant particles was studied using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Transmission electron microscopy images demonstrate growth of monodispersed gold seeds and Cu₂O nanoparticles in narrow size up to 10 nm and 5 nm, respectively. The presence of gold and Cu₂O coating was confirmed by X-ray diffraction, Fourier transform infrared spectroscopy and UV-Vis spectroscopy. Absorption spectroscopy shows considerably 40 nm blue shift in absorption edge for SiO₂-Au-Cu₂O nanostructure rather than SiO₂-Au core/shell nanoparticles.

7 illus, 20 ref

010481   Naveen Kumar;Sharma J D;Ahluwalia P K (Physics Dep, Shoolini University, Bajhol, Distt. Solan-173 212, Email: naveeenattri83@gmail.com) : First-principle study of nanostructures of functionalized graphene. Pramana J Phys 2014, 82(6), 1103-17.

Present first-principle calculations of 2D nanostructures of graphene functionalized with hydrogen and fluorine, respectively, in chair conformation. The partial density of states, band structure, binding energy and transverse displacement of C atoms due to functionalization (buckling) have been calculated within the framework of density functional theory as implemented in the SIESTA code. The variation in band gap and binding energy per add atom have been plotted against the number of add atoms, as the number of add atoms are incremented one by one. In all, 37 nanostructures with 18C atoms, 3 x 3 x 1 (i.e., the unit cell is repeated three times along x-axis and three times along y-axis) supercell, have been studied. The variation in C-C, C-H and C-F bond lengths and transverse displacement of C atoms (due to increase in add atoms) have been tabulated. A large amount of buckling is observed in the carbon lattice, 0.0053-0.7487 Angstrom, due to hydrogenation and 0.0002-0.5379 Angstrom, due to fluorination. As the number of add atoms (hydrogen or fluorine) is increased, a variation in the band gap is observed around the Fermi energy, resulting in change in behaviour of nanostructure from conductor to semiconductor/insulator. The binding energy per add atom increases with the increase in the number of add atoms. The nanostructures with 18C+18H and 18C+18F have maximum band gap of 4.98 eV and 3.64 eV, respectively, and binding energy per add atom -3.7562 eV and -3.3507 eV, respectively. Thus, these nanostructures are stable and are wide band-gap semiconductors, whereas the nanostructures with 18C+2H, 18C+4H, 18C+4F, 18C+8F, 18C+10F and 18C+10H atoms are small band-gap semiconductors with the band gap lying between 0.14 eV and 1.72 eV. Fluorine being more electronegative than hydrogen, the impact of electronegativity on band gap, binding energy and bond length is visible. It is also clear that it is possible to tune the electronic properties of functionalized graphene, which makes it a suitable material in microelectronics.

6 illus, 22 ref

010480   Nautiyal A;Upadhyay T C (Physics Dep, H N B Garhwal Univ, Srinagar, Garhwal-246 174, Email: ashishnautiyal05@rediffmail.com) : Soft mode and acoustic mode ferroelectric properties of deuterated triglycine sulphate crystal. Bull Mater Sci 2014, 37(1), 133-40.

A mathematical study about deuterated triglycine sulphate (CD₂CD₂COOD)₃D₂SO₄ crystal by a theoretical model which is extended with two sublattice pseudospin lattice coupled mode model by adding third, fourth and fifth order phonon anharmonic interaction terms as well as external electric field term in the crystal Hamiltonian. Double-time temperature dependent Green's function is used to derive soft mode frequency, dielectric permittivity, microwave absorption, quality factor, acoustic attenuation, electric conductivity, smooth function, relaxation time, ratio of figure of merits and respective applications in modern technologies. All theoretical results have a good agreement with experimental data.

14 illus, 1 table, 13 ref

010479   Nanayakkara A;Mathanaranjan T (NO, Institute of Fundamental Studies, Hanthana Road, Kandy, Sri Lanka, Email: asiri@ifs.ac.lk) : Effects of complex parameters on classical trajectories of Hamiltonian systems. Pramana J Phys 2014, 82(6), 973-83.

Anderson et al have shown that for complex energies, the classical trajectories of real quartic potentials are closed and periodic only on a discrete set of eigencurves. Moreover, recently it was revealed that when time is complex t (t=t_re^{iθ_t), certain real Hermitian systems possess close periodic trajectories only for a discrete set of values of θ_t. On the other hand, it is generally true that even for real energies, classical trajectories of non-PT symmetric Hamiltonians with complex parameters are mostly non-periodic and open. In this paper, we show that for given real energy, the classical trajectories of complex quartic Hamiltonians H=p 2+a x 4+b x k (where a is real, b is complex and k=1 or 2) are closed and periodic only for a discrete set of parameter curves in the complex b-plane. It was further found that the given complex parameter b, the classical trajectories are periodic for a discrete set of real energies (i.e., classical energy gets discretized or quantized by imposing the condition that trajectories are periodic and closed). Moreover, we show that for real and positive energies (continuous), the classical trajectories of complex Hamiltonian H = p2 + μx4, (μ = μ_reiθ are periodic when θ=4 tan-1[(n/(2m+n))] for ∀ n and m∈Z .}

4 illus, 26 ref

010478   Nadeem S;Saleem S (Mathematics Dep, Quaid-i-Azam University, 45320, Islamabad 44000, Pakistan, Email: salmansaleem_33@hotomail.com) : Series solution of unsteady eyrin powell nanofluid flow on a rotating cone. Indian J pure appl Phys 2014, 52(11), 725-37.

In the present paper, unsteady mixed convective flow on a rotating cone in a rotating nano Eyring Powell nanofluid has been studied. It has been revealed that a self-similar solution is only possible when the free stream angular velocity and the angular velocity of the cone are inversely proportional to a linear function of time. The boundary layer equations are reduced to the nonlinear ordinary differential equations using similarity and non-similarity transformations. The reduced coupled nonlinear differential equations for rotating cone are solved by optimal homotopy analysis method. The physical behaviour of pertinent parameters has also been studied through the graphs of dimensionless velocities, temperature, nano particle volume fraction, skin friction, Nusselt number and Sherwood number. Numerical results for important physical quantities are reported.

8 illus, 5 table, 34 ref

010477   Murthy M V V;Brack M;Bhaduri R K (Institute of Mathematical Sciences, , Chennai-600 113, Email: murthy@imsc.res.in) : A phenomenological approach to the equation of state of a unitary Fermi gas. Pramana J Phys 2014, 82(6), 985-93.

We propose a phenomenological approach for the equation of state of a unitary Fermi gas. The universal equation of state is parametrized in terms of Fermi-Dirac integrals. This reproduces the experimental data over the accessible range of fugacity and normalized temperature, but cannot describe the superfluid phase transition found in the MIT experiment [Ku et al, Science 335, 563 (2012)]. The most sensitive data for compressibility and specific heat at phase transition can, however, be fitted by introducing into the grand partition function a pair of complex conjugate zeros lying in the complex fugacity plane slightly off the real axis.

4 illus, 14 ref

010476   Mounkachi O;Salmani E;Boujnah M;Labrim H;El Moussaoui H;Hamedoun M;Benyoussef A;El Kenz A;Ez-Zahraouy H;Masrour R (Instituter for Nanomaterials and Nanotechnology, MAScIR (Moroccan Foun, , Rabat, Morocco) : High temperature magnetic properties of nanocrystalline Sn_0ù95Co_0ù05O₂. Bull Mater Sci 2014, 37(3), 563-9.

Structural and magnetic properties of Sn_0ù95Co_0ù05O₂ nanocrystalline and diluted magnetic semiconductors have been investigated. This sample has been synthesized by co-precipitation route. Study of magnetization hysteresis loop measurements infer that the sample of Sn_0ù95Co_0ù05O₂ nanoparticle shows a well-defined hysteresis loop at 300 K temperature, which reflects its ferromagnetic behaviour. We confirmed the roomtemperature intrinsic ferromagnetic (FM) semiconductors by ab initio calculation, using the theory of the functional of density (DFT) by employing the method of Korringa-Kohn-Rostoker (KKR) as well as coherent potential approximation (CPA, explain the disorder effect) to systems. The ferromagnetic state energy was calculated and compared with the local-moment-disordered (LMD) state energy for local density approximation (LDA) and LDA-SIC approximation. Mechanism of hybridization and interaction between magnetic ions in Sn_0ù95Co_0ù05O₂ is also investigated. To explain the origin of ferromagnetic behaviour, we give information about total and atoms projected density of state functions.

10 illus, 1 table, 32 ref

010475   Motevalizadeh L;Heidary Z;Ebrahimizadeh Abrishami M (Physics Dep, Mashhad Branch, Islamic Azad University, Mashhad, Iran, Email: ebrahimizadeh@ymail.com) : Facile template-free hydrothermal synthesis and microstrain measurement of ZnO nanorods. Bull Mater Sci 2014, 37(3), 397-405.

ZnO nanorods were synthesized at low temperature by hydrothermally heating 0.1 M solution of ZnCl₂ for 5, 10 and 15 h at a pH of 10. No template, seeded substrate, catalyst and autoclave were employed for the synthesis of ZnO nanorods. The effect of heating durations on the morphology and crystal orientation of the structure were investigated by using scanning electron microscopy and X-ray diffraction, respectively. SEM images showed that the flower-like structures were formed in 5 h hydrothermally-heated sample, whereas the hexagonal zinc oxide nanorods were perfectly fabricated with the increase in growth time. XRD patterns showed that the preferred orientation in nanorods could be controlled by hydrothermal treatment time. The crystallite size and microstrain were analysed by Williamson-Hall and Halder-Wagner methods. These results revealed the presence of defects in ZnO nanorods. However, by increasing the hydrothermal treatment time, both defects in lattice and crystallite size are decreased.

8 illus, 3 tables, 42 ref

010474   Lian-Fang H;Hao Y;Ming Y;Zhuo-Liang C (School of Physics and Material Science, Anhui Univ, Hefei 230039, China, Email: lianfanghan@gmail.com) : Assisted cloning of an arbitrary unknown two-qubit state via a genuine four-qubit entangled state and positive operator-valued measure. Indian J pure appl Phys 2014, 52(8), 563-70.

A protocol for cloning an arbitrary unknown two-qubit state and its orthogonal complement state with the assistance of a state preparer is presented. In this paper, a genuine four-particle entangled state which cannot be reduced to the product of two Bell states is used as the quantum channel. Moreover, positive operator-valued measure (POVM) instead of usual projective measurement is employed. In one hand, the usual teleportation is required. And in another hand, the perfect copies and complement copies of an unknown two-particle state can be implemented with a certain probability in the help of the state preparer.

3 tables, 52 ref

010473   Jaggi N;Yadav K;Giri M (Physics Dep, National Institute of Technology, Kurukshetra-136 119, Email: neena_jaggi@rediffmail.com) : Static studies of absorption and emission spectra of acid yellow 17-An azo dye. Indian J pure appl Phys 2014, 52(11), 742-6.

In the present paper, the absorption and emission spectra of acid yellow 17 (C₁₆H₁₀C_l2N₄Na₂O₇S₂), a fluorescent azo dye, have been recorded in water at oncentrations between 10^{-3 M and 10-6 M. This dye is used in many scientific and industrial applications. This has led to the determination of optimum concentrations to record the absorption and emission spectra of the molecule. The absorption spectrum shows three peaks at 224, 254 and 400 nm, recorded in the spectral region 200-600 nm, which have been assigned to (π*←π) 1L_a ← 1A (primary), (π*←π) 1L_b← 1A (secondary) and (π* ←n)1 W ←1A transitions, respectively. Emission spectra of the compound show four peaks at 295, 306, 412 and 437 nm corresponding to absorption peaks at 224, 254 and 400 nm. Their corresponding Stokes shifts have also been determined.}

8 illus, 26 ref

010472   Horng J W;Wu C M;Herencsar N (Electronic Engineering Dep, Chung Yuan Christian Univ, Chung-Li, 32023, Taiwan, Email: jwhorng@cycu.edu.tw) : Three-input-one-output current-mode universal biquadratic filter using one differential difference current conveyor. Indian J pure appl Phys 2014, 52(8), 556-62.

A current-mode universal biquadratic filter is presented. The architecture has three input terminals, one output terminal using one differential difference current conveyor (DDCC), two grounded capacitors and two resistors. It can realize all standard second-order filter functions, which are, highpass, bandpass, lowpass, notch and allpass responses without changing the circuit topology. The proposed circuit employs only one DDCC that simplifies the circuit configuration.

10 illus, 1 table, 18 ref

010471   Hasanbeigi A;Farhadian A;Khademi Bidhendi E (Physics and Institute for Plasma Research, Kharazmi University, , 43 Dr Mofatteh Avenue, Tehran 15614, Iran, Email: hbeigi@khu.ac.ir ) : Growth rate enhancement of free-electron laser by two consecutive wigglers with axial magnetic field. Pramana J Phys 2014, 82(6), 1049-60.

The operative mechanism for a free-electron laser (FEL) with two consecutive helical wigglers having opposite circular polarization in the presence of an axial magnetic field is proposed and analysed. With the help of fluid theory, a tenth-degree polynomial dispersion equation for electromagnetic and space-charge waves is derived. The results are used to illustrate and discuss the dependence of growth rate on different system parameters. Finally, it is shown that for the same system parameters the growth rate of the proposed structure is more than the growth rate of instability in a conventional FEL.

7 illus, 20 ref

010470   Hadasa K;Yellaiah G;Nagabhushanam M (Physics Dep, Univ College of Science, Osmania Univ, Hyderabad-500 007, Email: mamidala_nb@yahoo.com) : Effect of copper doping on structural, optical and electrical properties of Cd_0.8Zn_0.2S films prepared by chemical bath deposition. Bull Mater Sci 2014, 37(1), 53-60.

Cd_0.8Zn_0.2S:Cu films of 1.3-6.1 mole percentage of copper have been grown on mica substrate by using chemical bath deposition technique. The films have been characterized by using XRD, SEM and UV spectrophotometer. X-ray diffraction studies have shown that the films are polycrystalline. The average crystallite size as measured from XRD data is in the range of 125-130 nm. The activation energies of Cd_0.8Zn_0.2S:Cu films, as observed from d.c. conductivity studies in the temperature range (77-300 K) studied, decreased with the increase in Cu concentration. The optical absorption studies have revealed that the energy gap increases gradually with an increase in Cu concentration, whereas conductivity studies have shown an anomalous increase in conductivity in films of 3.8 mole percentage of Cu. SEM pictures have revealed the presence of defects with spherical structure having fibre network. The variation of electrical conductivity is explained based on the defects present and by adopting tunneling mechanism.

7 illus, 5 tables, 29 ref

010469   Gupta M M;Medhekar S (Centre for Applied Physics, Central University of Jharkhand, Ranchi-835 205, Email: smedhekarbit@gmail.com) : Switching behaviour of nonlinear Mach-Zehnder interferometer based on photonic crystal geometry. Pramana J Phys 2014, 82(6), 1061-74.

Nonlinear Mach-Zehnder interferometer (NMZI) created with photonic crystal waveguides (PCW) and with Kerr-type nonlinearity has been investigated in this paper. The NMZI has been simulated using two-dimensional finite difference time domain (2D-FDTD) method. Input verses output (I /O) characteristics have been obtained for different lengths of the nonlinear arm, nonlinear coefficients of the nonlinear arm, wavelengths of the input beam, sizes of defect rods and NMZI offset. The results obtained are compared with earlier published results of NMZI created with conventional step index waveguides (SIW). It is shown that all useful features of light switching offered by SIW-based NMZIs are also possible with PCW-based NMZIs of extremely small dimensions. Moreover, PCW-based NMZIs offer additional useful feature not available with SIW-based NMZIs.

7 illus, 29 ref

010468   Gupta A K;Ujjwal S K (Physics Dep, Jai Narain Vyas University, Jodhpur-342 005, Email: anupgupta58@gmail.com) : Absorption spectra of ternary complex of neodymium in different solvents. Indian J pure appl Phys 2014, 52(11), 738-41.

The optical absorption spectra of complex of neodymium in different solvents i.e water (18), methanol (32.04), ethanol (46.07) and acetic acid (60.05) have been recorded in visible region (360-900 nm for Nd3+) using amino acid primary ligand and diol as secondary ligand in ratio (1:2:1). The values of energies and intensities of various transition have been calculated using Judd-Ofelt relation which are found to be in good agreement with experimental results. The complexes studied are found to be ionic in nature. The effect of various ligand on the position and intensity of the observed transition in different environments has been discussed in terms of metal-ligand co-ordinate. Transition also involves change in the vibrational modes of the complex comprising a rare earth ion and its surroundings which provides a contribution to oscillator strength of precisely similar form.

6 tables, 22 ref

010467   Enamullah;Vipin Kumar;Upendra Kumar; (Physics Dep, Indian Institute of Technology Huwahati, Guwahati-781 039, Email: enamullah@iitg.ernet.in) : Theoretical study of pump-probe experiment in single-layer, bilayer and multilayer graphene. Pramana J Phys 2014, 82(6), 1085-101.

The pump-probe experiment is typically used to study relaxation phenomena in nonlinear optical systems. Here we use it as a tool to study the phenomenon of anomalous Rabi oscillations in graphene that was predicted recently in single-layer graphene. Unlike conventional Rabi oscillations, anomalous Rabi oscillations are unique to graphene (and possibly to surface states of topological insulators (TIs)), attributable to the pseudospin (conventional spin for TI) degree of freedom and Dirac-fermion character of the graphene system. A pump pulse of a finite duration long enough to contain a large number of cycles induces a current density that oscillates with the frequency of the pump pulse. The amplitude associated with these fast oscillations is seen to exhibit much slower oscillations with a frequency given by 2ω^{2_R/ω - the anomalous Rabi frequency, where ? R is the conventional Rabi frequency and ωR is the frequency of the external pump field. This effect is easily probed by a probe pulse subsequent to the pump, where it manifests itself as periodic oscillations of the probe susceptibility as a function of pump duration at each probe frequency. Alternatively, it is also seen as an oscillatory function of the pump-probe delay with other variables remaining fixed. This period corresponds to the anomalous Rabi frequency. An analysis of the previously reported experimental data confirms the presence of anomalous Rabi oscillations in graphene.}

2 illus, 29 ref

010466   Emdadifard M;Hosseini S M M M (Civil Engineering Dep, Amirkabir Univ of Technology, Tehran, Iran, Email: smmirhos@aut.ac.ir) : Study of the parameters of coefficient of friction, porosity, particle diameter, density and dispersity on wave propagation velocity. Biosci Biotechnol Res Asia 2014, 11(2), 635-40.

In the present paper, discrete element method (DEM) is used to study wave propagation phenomenon in granular soils. The effect of factors such as coefficient of friction, porosity, particle diameter, density and dispersity on the wave speed is studied. Using the wall motion based on the sinusoidal function is the method of loading used in this simulation, through which the pressure wave is transferred to particles. Simulations results are well consistent with the results of experiments conducted by other researchers. In addition, the results obtained are shown as graphs to study the effectiveness of each parameter. According to the results, the coefficient of friction, porosity and density have a greater effect on the wave speed.

6 illus, 18 ref

010465   Dyako;Mostafavi;Yadollahpour A;Aghdami K M (Physics Dep, Islamic Azad Univ, Boukan branch, Boukan, Iran, Email: diya_nano21@yahoo.com) : Spatial discrete soliton in homogeneous two dimensional waveguide arrays with kerr medium. Biosci Biotechnol Res Asia 2014, 11(2), 979-83.

Behaviors of discrete spatial solitons in nonlinear mediums have recently received a plenty of research interest. In this study, for the first time, the effects of diagonal neighbors on spatial discrete solitons in a two dimensional waveguide with Kerr medium are investigated. A numerical model for propagation of the Gaussian beam through a two dimensional waveguides array is proposed. The waveguide contains medium with Kerr nonlinearity considering coupling to vertical, horizontal and diagonal neighbor through light electric field. Different values of intensity, nonlinear coefficient Kerr and Gaussian beam width of incident Gaussian beam are examined and finally suitable parameters for providing central spatial solutions are obtained.

5 illus, 14 ref

010464   Dutta S;Chattopadhyay P (Electronic Science Dep, University of Calcutta, Kolkata-700 009, Email: pcelc@caluniv.ac.in ) : Saturated velocity model of MESFET in the presence of non-uniform distribution of channel impurities and interface states at the gate contact. Indian J pure appl Phys 2014, 52(11), 783-8.

A comparative analysis of the electrical properties of a metal-semiconductor field effect transistor operated in the region of electron velocity saturation has been studied for different types of impurity profiles and taking into considerationthe effects of interface states and interfacial layer at the gate contact of the device. Particularly, the power law, exponential and Gaussian impurity profiles in the channel have been considered.The variations of space charge density and depletion layer width with drain voltage and interface state density for the above impurity profiles have been studied relative to that of uniform distribution of doping. The expressions for drain current for these doping profiles have been derived. The normalized current relative to that of uniform distribution of impurities has been studied as a function of drain voltage and interface state density for the respective doping profiles.

3 illus, 2 tables, 25 ref

010463   Deepika B;Pillai B;Nair S V;Subramanian K R V (Amrita Centtre for Nanosciences and Msolecular Medicine, , Ponekkara P.O., Kochi-682 041, Email: krvsubramanian@aims.amrita.ed) : Development of a new solid-state absorber material for dye-sensitized solar cell (DSSC). Bull Mater Sci 2014, 37(3), 685-93.

In contrast to the conventional DSSC systems, where the dye molecules are used as light harvesting material, here a solid-state absorber was used as a sensitizer in conjunction with the dye. The materials like ZnO and Al₂O₃ : C, which will show optically stimulated luminescence (OSL) upon irradiation were used as extremely thin absorber layers. This novel architecture allows broader spectral absorption, an increase in photocurrent, and hence, an improved efficiency because of the mobility of the trapped electrons in the absorber material after irradiation, to the TiO₂ conduction band. Nanocrystalline mesoporous TiO₂ photoanodes were fabricated using these solid-state absorber materials and after irradiation, a few number of samples were co-sensitized with N719 dye. On comparing both the dye loaded photoanodes (ZnO/TiO₂ and Al₂O₃ : C/TiO₂), it can be concluded from the present studies that, the Al₂O₃ : C is superior to ZnO under photon irradiation. Al₂O₃ : C is more sensitive to photon irradiation than ZnO and hence there can be more trap centres produced in Al₂O₃ : C.

11 illus, 5 tables, 13 ref

010462   De S (Variable Energy Cyclotron Centre, , 1/AF Bidhan Nagar, Kolkata-700 064, Email: somvecc@gmail.com) : Extent of sensitivity of single photon production to parton distribution function. Pramana J Phys 2014, 82(6), 1039-47.

Studied the production of single isolated prompt photons in high-energy proton-proton collisions at the RHIC (√ s= 200 GeV) and the LHC ( √s = 7 TeV) energies within the framework of perturbative QCD upto next-to leading order of strong coupling (α s). We have used five different parametrizations of parton distribution function (PDF) starting from the old CTEQ4M to the new CT10 distributions and compared our results with the recent single-prompt photon data from the PHENIX and the CMS Collaborations. The prompt photon cross-section is found to be described equally well by all the PDFs within the experimental errors at the RHIC and the LHC energies. The deviation in the single-prompt photon yield for different PDF sets is within ±20% when compared to CTEQ4M, indicating the upper bound of uncertainty in determining the gluon density. The diphoton measurement could be a potential candidate to constrain the gluon distribution inside the proton.

5 illus, 30 ref

010461   Daivajna M D;Neeraj Kumar;Gahtori B;Awana V P S;Kuo Y K;Rao A (Physics Dep, Manipal Institute of Technology, Manipal Univ, Manipal-576 104, Email: ashokanu_rao@rediffmail.com) : Electrical conduction and thermal properties of Bi-doped Pr_0.7Sr_0.3MnO₃ manganite. Bull Mater Sci 2014, 37(1), 47-51.

Electrical and thermal properties of Bi-doped Pr_0.7Sr_0.3MnO₃ (PSMO) compounds are reported here. It is observed that Bi-doped PSMO compounds follow variable range conduction mechanism. Specific heat, thermal conductivity and thermo-power measurements show that larger Bi-ion, in place of smaller Pr ion, enhances their transition temperatures (T_MI, T_C, T_CP). Thermo-power measurements further strengthen our conclusion for the presence of magnetic polaron, generated due to hybridization of Bi^{3+-6s2 and O2--2p orbital and polaronic conduction mechanism.}

5 illus, 2 tables, 21 ref

010460   Chatterjee S;Chowdhury S K;Sarkar P P;Sarkar D C (ECE Dep, West Bengal University of Technology, RCC Institute of Information Tec, Beliaghata, West Bengal, Email: samiranengineer@gmail.com) : Bevel microstrip printed antenna for satellite communication. Indian J pure appl Phys 2014, 52(11), 760-6.

A single feed, single layer compact bevel cut rectangular patch antenna is proposed. The bevels are cut at the left-top corner and the right-bottom corner. The 1st resonant frequency (4.25 GHz) is applicable for short band radio wave communication and the other resonant frequency (6.93 GHz) is applicable for radar communication. All the results are simulated by using IE3D, a MoM based software and the results are verified by the VNA network analyzer. This paper includes the bandwidth, return loss, vswr range and radiation pattern.

15 illus, 2 tables, 21 ref

010459   Chakrabarti B;Ghosh D;Mitra M (ECE Dep, Bengal Institute of Technology, Kolkata 150, Email: dg1036@gmail.com) : Comparative analysis of the millimeter wave performance of diamond based IMPATT diode with that of SiC (4H) IMPATT diode. Indian J pure appl Phys 2014, 52(11), 776-82.

A detailed comparative analysis of the diamond semiconductor based DDR IMPATT devices in W-band has been carried out (normal and photo illuminated) through a simulation scheme. The simulation results reveal that an optimized unilluminated diamond IMPATT diode of efficiency 18.45% can be realized, whereas 4H-SiC IMPATT can have efficiency of 11.97%. Under optical illumination, the admittance and negative resistance values of the IMPATT diode degrade due to additional photo generated carriers. The negative conductance (-G) and total negative resistance (-ZR) of the diamond based DDR IMPATT diode decrease by 7.03% and 8.5%, respectively when the diode is exposed to photo illumination whereas, for SiC based diode the decrements are 6.06% and 6.09%, respectively. Moreover under optical illumination, the quality factor (Qp) of diamond IMPATT increases by 22.5% and it is only 6.5% for SiC based devices. Therefore, from the simulation work it is well established that, though the photosensitivity of 4H-SiC based IMPATT is better than its diamond counterpart the overall small signal performance of the illuminated diamond IMPATT degrades far more than SiC based devices due to very high reported carrier ionization rates in diamond. The simulation results also reveal the superiority of diamond based IMPATT device in terms of heat sink design in comparison to 4H-SiC based devices.

5 illus, 3 tables, 26 ref

010458   Binitha P M;Pradyumnan P P (Physics Dep, University of Calicut, Calicut-673 635, Email: binithamp@gmail.com) : Growth, characterization and dielectric property studies of gel grown barium succinate single crystals. Bull Mater Sci 2014, 37(3), 491-5.

Single crystals of barium succinate (BaC4H4O4) were grown in silica gel medium using controlled chemical reaction method. Plate-like single crystals of size up to 3 x 2 x 02 mm3 was obtained. Single crystal X-ray diffraction (XRD) studies confirmed that structure of the title compound is tetragonal. Powder X-ray diffraction (PXRD) pattern of the grown crystal and the Fourier transform infrared (FT-IR) spectrum in the range 400-4000 cm-1 are recorded. The vibrational bands corresponding to different functional groups are assigned. Thermal stability of the grown crystals is confirmed by differential scanning calorimetry (DSC). Dielectric constant and dielectric loss have been calculated and discussed as a function of frequency at different temperatures.

7 illus, 2 tables, 16 ref

010457   Binitha M P;Pradyumnan P P (Physics Dep, University of Calicut, Calicut-673 635, Email: binithamp@gmail.com) : Growth, characterization and dielectric property studies of gel grown barium succinate single crystals. Bull Mater Sci 2014, 37(3), 491-5.

Single crystals of barium succinate (BaC₄H₄O₄) were grown in silica gel medium using controlled chemical reaction method. Plate-like single crystals of size up to 3 x 2 x 0.2 mm^{3 was obtained. Single crystal X-ray diffraction (XRD) studies confirmed that structure of the title compound is tetragonal. Powder X-ray diffraction (PXRD) pattern of the grown crystal and the Fourier transform infrared (FT-IR) spectrum in the range 400-4000 cm-1 are recorded. The vibrational bands corresponding to different functional groups are assigned. Thermal stability of the grown crystals is confirmed by differential scanning calorimetry (DSC). Dielectric constant and dielectric loss have been calculated and discussed as a function of frequency at different temperatures.}

7 illus, 2 tables, 16 ref