012466   Hong S S;Khan W;Kang S W (Vacuum Technology Center, KRISS, Daejeon 305-340, Republic of Korea, Email: sshong@kriss.re.kr) : Investigation of a set procedure for the stability of pressure control in the newly developed flow-control system at KRISS. MAPAN 2009, 24(2), 89-94.

Korea Research Institute of Standards and Science (KRISS) has assembled a new flow-control system (FCS-705) for the study of advanced applications and calibration of different types of vacuum gauges by comparison method. Details the measurement of the outgassing rate of the main vacuum chamber by the pressure rate of rise method. Constant pressure was generated inside the vacuum chamber by employing a dynamic flow control method. Nitrogen gas flow data was recorded to demonstrate that constant pressure was controlled in the vacuum chamber. The measurements were performed in a sequence of increasing pressures.

5 illus, 3 tables, 10 ref

012465   Gaurav S K;Birajdar A A;Patange S M;Lohar K S;Mane D R (Physics Dep, S.M.P. College, Murum) : Structural and magnetic properties of lanthanium subsituted copper cadmium ferrites. Bionano Front 2010, NCANDT(spl), 160-5.

Polycrystalline copper -cadmium ferrite samples having formula Cu_0.7Cd_0.3Fe₂O₄ in which lanthanum dopants added, were prepared by auto combustion method. The structure of synthesized samples confirmed by X- ray diffraction technique revels formation of single- phase cubic structure. The values of lattice constant decreases with doping concentration increases. The X- ray density decreases with concentration of lanthanum increases with contents x, particle size is observed in few nm. The saturation magnetization and magnetron number measured at 300K measured from high field hysteresis loop method decreases with increase in concentration x deprecating a decreasing in ferrimagnetic behaviour. Thramal variation of low field a.c. susceptibility measurement from room temperature to 800K shows normal ferrimagnetic behavior. Cure temperature measured from d.c. restivity and a.c. susceptibility measurement.

2 illus, 2 tables, 21 ref

012464   Ekhelikar S;Roy A S;Anilkumar K R;Patil R; Ambika Prasad M V N (Physics Dep, N.V. Degree College, Gulbarga, Karnataka, Email: shrikant_ek@yahoo.com) : Synthesis, characterization and DC conductivity studies on polyaniline doped with nano-copper oxide. Bionano Front 2010, NCANDT(spl), 6-11.

A double-surfactant-layer-assistant polymerization method was designed to prepare well-controlled core/shell metal oxide/polyaniline (c/s-MO/PANI) nanocomposites. Monodispersed and uniform core/shell nanocomposites c/s-CuO/PANI with different weight percentage were successfully prepared using this polymerization method. By the removal of the cores for the resulting c/s-CuO/PANI nanocomposites, hollow PANI capsules with different shapes and sizes were obtained. The method provides an effective way to design novel core/shell nanostructures with high colloidal stability. The synthesized c/s-CuO/PANI composites are characterized by FTIR for its polymerization, XRD for its semi-crystalline behavior and SEM for nanosized CuO. The composites show thermally activated hopping behavior.

7 illus, 26 ref

012463   Dhumure S S (Physics Dep, Ramkrishna Paramhansa Mahavidyalaya, Osmanabad-431 501) : Nanotechnology: an emerging area of science. Bionano Front 2010, NCANDT(spl), 211-13.

012462   Dhage V N;Babrekar M K;More S D;Dindore U B; Jadhav K M (Physics Dep, Dr. Babasaheb Ambedkar Marathwada Univ, Aurangabad, Maharashtra) : Effect of fuel ratio on the structural and magnetic properties of hexagonal ferrite. Bionano Front 2010, NCANDT(spl), 226-30.

Nanosized barium hexaferrite samples with varying fuel ratio have been synthesized successfully by using sol-gel auto-combustion technique. In this process citric acid is used as fuel. The ratios of cation to citric acid maintained variously as 1:2, 1:3 whereas the pH of the sample was kept constant at 8. The samples were sintered at 1250°C for 6 h. to form the nanosized bariumhexaferrite sample. The structural characterization of the samples was made using X-ray diffraction technique. XRD pattern clearly indicate the formation of single phase barium hexaferrite. The most intense peak of XRD pattern was used to evaluate particle size. The particle size obtained from XRD data was in the range of 30-40 nm. for both 1:2 and 1:3 nitrate to fuel ratio. The lattice constantants calculated from XRD was in the reported range. The saturation magnetization, coercivity, rermanence ratio etc magnetic properties were investigated. The results of X-ray diffraction and magnetization measurement reveals the BaFe₁₂O₁₉ hexaferrite obtained by 1:2 nitrate to fuel ratio shows good properties than 1:3 ratio.

2 illus, 2 tables, 21 ref

012461   Detian L;Guangping Z;Meiru G;Jie X;Yongjun C (NO, National Key Lab of Vacuum and Cryogenics Technology and Physics, Lanz, Lanzhou 730000, China, Email: chyj750418@163.com) : Static expansion vacuum standard with extended low pressure range. MAPAN 2009, 24(2), 95-100.

Main factor to affect lower limit of static expansion vacuum standard is outgassing of the inner surface. A new method has been demonstrated to extend the lower limit by using a non-evaporable getter pump (NEGP) to eliminate the outgassing influence. Because NEGP has no pumping speed for inert gases, it can maintain the ultra-high vacuum background without changing gas quantity in the calibration chamber when an inert gas is used as the test gas, which makes the standard pressure accurately calculable by Boyle's law. By this method, the lower limit of static expansion vacuum standard has been extended to 10^{-7 Pa.}

4 illus, 10 ref

012460   Dehingia N;Konwar M;Baruah G D (Physics Dep, Dibrugarh Univ, Dibrugarh-786 004, Email: gadbaruah@rediffmail.com) : Laser induced fluorescence of namsai meteorite. Asian J Phys 2009, 18(1), 127-30.

Laser induced fluorescence spectrum of Namsai meteorite has been excited with the help ofa 25 mW Green (532 nm) solid state laser and photographed on a glass spectrograph in the range of wavelength 5400-6500 A. The spectrum is diffused. The band system is attributed to silicate (olivine), a major component of the meteorite. A comparison of the emission system with that of Dergaon meteorite has been made.

2 illus, 11 ref

012459   Chouhan N;Kalra M L;Ameta S C (Chemistry Dep, Government P G College, Bundi-323 001, Email: niloochauhan@hotmail.com ) : Investigation of electronic transport in the novel charge transfer complex p-cresol(TCNQ)₂. Asian J Phys 2009, 18(1), 89-94.

The charge transfer complex p-cresol(TCNQ)₂, prepared by solution growth method, belongs to the monoclinic crystal system with space group P2_1/m and cell parameters a = 6.892 Angustrum, b = 17.379 A, c = 17.888 A, β = 93.737 °, Z = 8, d = 2. 41 g cm^-3, V = 2138 Angustrum³. It was characterized by elemental analysis, UV-Vis, NMR, XRD and SEM. DC conductivity measurements showed that this quasi one dimensional complex was semiconducting till 433 K with σ _RT =1.4103 x 10^-11 Ω^-1 cm^-1 and E_a = 0.0921 eV, while it exhibited constant resistivity (38.40 x 10³ Ω cm) in the temperature range 433-543 K.

5 illus, 18 ref

012458   Chopra K N;Joseph J;Singh K (Physics Dep, Indian Institute of Technology Delhi, New Delhi-110 016, Email: joby@physics.iitd.ac.in) : Negative refraction metamaterials, geometrical transformations, cloaking, and related areas-a qualitative bibliographic review for the year 2008. Asian J Phys 2009, 18(1), 17-56.

The negative refractive materials (NRMs) exhibit a number of interesting properties e.g. refraction of light entering the material, on the same side of the normal; reversal of Doppler shift, and the time-averaged Poynting vector being **parallel to phase velocity, implying that the wavefronts move in the direction opposite to the flow of energy. because of the interesting properties associated with these materials, many researchers are engaged in the investigations ** various related topics like superlenses, superresolution, reduced beam-squinting on printed leaky-wave antennas, wave propagation, equivalent circuit models, polaritons, solitons, plasmonic waveguides, Goos-Hanchen shift, and ** etc. A qualitative review of the studies made in the field of negative refraction in the year 2008 has been given in this paper. Although an attempt has been made to include as many papers as possible, no claim is made as to the completeness. Inadvertent omission in citing of the work by other researchers is very much regretted. Anita Publications. All rights reserved.

26 ref

012457   Chaudhari V A;Pawar P P;Bichile G K (Physics Dayanand Science College Dep, , Latur-413 531, Email: vijendra333@gmail.com) : Sol-gel synthesis and effect of particle size of lead titanate nanoparticles. Bionano Front 2010, NCANDT(spl), 172-5.

Ferroelectric lead titanate powders have been prepared by sol-gel method using acetylacetone chelating with titanium isopropoxide and ethylene glycol as a solvent. The phase purity, particle size and morphology are studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. It is also confirmed from X-ray patterns that the tetragonal perovskite structure of the titanate exists without any impurity peaks.

3 illus, 12 ref

012456   Chaudhari N D;Bhosale D N;More R M;Sharma B R;Suryawanshi S S;Sawant S R (NO, , Pratishthan Mahavidyalaya, Paithan, Dist.Aurangabad, Maharashtra) : Initial permeability and loss factor studies on Li<. Bionano Front 2010, NCANDT(spl), 117-19.

The synthesized various compositions of Ni_0.32Zn_0.68-XLi_XFe_2-XO₄ ferrite system by using soft chemistry route using oxalate precursors. Compositional and thermal variation of initial permeability and loss factor was carried out from room temperature to Curie temperature. Variation of initial permeability with addition of Li¹⁺ has been explained by considering the variation of saturation magnetization and anisotropy constant. The dominant contribution to u. is found to be due to wall motion. Loss factor increases with increase in Li¹⁺, which is due to decrease in initial permeability. A small value of loss factor is attributed to the processing techniques.

2 illus, 1 table, 14 ref

012455   Birajdar C T;Mane M L;Dhage V N;Babrekar M K; Jadhav S P;Jadhav K M (NO, , S.M.P.M. Murum, Omerga, Osmanabad, Maharashtra) : Synthesis, structural and magnetic properties of magnesium ferrite nano-particles. Bionano Front 2010, NCANDT(spl), 176-80.

Nano particles of Magnesium spinel ferrite (MgFe₂O₄) have been prepared by wet chemical co-precipitation technique at low temperature. The wet samples were annealed at 600 °C in order to obtain complete ferrite phase. The conformation of nanosized particles was carried out using X-ray diffraction and scanning electron microscopy techniques. X-ray diffraction results showed that the sample was in single phase with space group Fd3m-O⁷Z_h. The XRD data was used to investigate the structural properties such as lattice constant, particle size, X-ray density, porosity etc. The crystallite site was calculated from XRD data and is found to be in nanometer dimension. The magnetic properties were investigated using pulse field hysteresis loop technique. The large value of coercivity indicates the nanosized nature of the MgFe₂O₄. The results obtained on the structural and magnetic properties of nanosized magnesium ferrite are reported in this work.

4 illus, 2 tables, 16 ref

012454   Birajdar A A;Gaurav S K;Patange S M;Lohar K S;Mane D R;Shitre A R;Jadhav K M (Physics Dep, S.M.P. College, Murum) : Investigation of structural and electrical properties of Ni_0.7Zn _0.3 Al_x Fe_2-x O₄ system synthesiesed by autocombusition method. Bionano Front 2010, NCANDT(spl), 140-4.

A series of polycrystalline spinel fertile with composition Ni_0.7Zn_0.3Al_x Fe_2-xO₄ where (x=0.0,0.1,0.2,0.3,0.4,0.5) where synthesized by Autocombusition method from corresponding metal nitrates. The x-ray diffraction analysis showed that all samples having single phase cubic spinel structure. The lattice constant a is decreases with increased the increasing concentration of Al⁺³ ions. The IR spectrum shows to main absorption band respectively. The D.C electrical conductivity increases with increasing temperature insuring indicating the semiconducting nature of sample. The Curie temperature determined from D.C electrical conductivity is decreasing with increase in concentration of Al⁺³ ions.

2 illus, 3 tables, 10 ref

012453   Bavane R G;Gore R B;Borkar P;Mahajan A M (School of Physical Sciences, North Maharashtra Univ, Jalgaon-425 001) : Characterization of pani films prepared by chemical synthesis technique. Bionano Front 2010, NCANDT(spl), 218-20.

In the present work the conducting polymer, polyanilme/(PANI) was prepared by chemical oxidative polymerization. The NMP (n-methylpyrrolidone) was used as a solvent to prepare a thin film from synthesized PANI powder with the help of spin coating technique. The chemical composition of the synthesized conducting polymer is determined with FTIR spectroscopy. The FTIR characterization confirms the formation of PANI films through the presence of peaks at 1185, 1460,1530 and 1480 cm^{-1due to vibrations of C-N-C, C=C, benzenoid and quinoid rings respectively. The ohmic behavior of synthesized PANI film was also observed at room temperature by I-V characteristics.}

3 illus, 14 ref

012452   Basavaraja S;Sankarappa T;Mathad R D; Krishnamurthy B S (Physics Dep, Gulbarga Univ, Gulbarga-585 106, Email: sankar@rediffmail.com) : Suppression of rayleigh-taylor instability in plasma by the transverse magnetic field. Asian J Phys 2009, 18(1), 113-20.

The effect of transverse magnetic field on the Rayleigh-Taylor instability in a thin layer of viscous and electrically conducting plasma has been examined using the linear theory in the creeping flow limit. The growth rate of the instability-was found to be controlled by the thickness of the plasma layer, ratio of surface tension to the stress gradient and the Chandrashekhar number which was a function of an applied transverse field. It also revealed that the transverse field prevent the growth of finger instabilities which exist for thick films. The growth rate of the instability is found to be exponentially decaying with the transverse magnetic field.

7 illus, 12 ref

012451   Bajpeyee A U;Pawar B H;Chaudhari G N;Kapse V D;Murade P A (Physics Dep, Arts Science and Commerce College, Amravati-444 606) : Preparation of nanostructured Fe_2.939O₄ ceramic. Bionano Front 2010, NCANDT(spl), 195-7.

A sol-gel process was developed for preparing cubic structured nanocrystalline Fe_2.939 powder by ethylene glycol mediated citrated sol-gel method. The structural evolution has been systematically investigated by X-ray diffraction (XRD). Nanocrystalline powder of ~23 nm size could be obtained at a temperature of 600 °C.

1 illus, 7 ref

012450   Alone S T;Kadam R H;Shirsath S E;Jadhav K M (NO, Vidya Pratishtan's Polytechnic College Indapur, Pune, Maharashtra) : D.C. electrical resistivity and infrared spectroscopic study of Co_1-xZn_xFe_2-xCr_XO₄. Bionano Front 2010, NCANDT(spl), 23-6.

Spinel ferrites having the general formula Co_1-xZn_xFe_2-xCr_xO₄ (x = 0.1, 0.2, 0.3, 0.4, 0.5) were prepared using the wet chemical co-precipitation technique. The samples were annealed at 800nC temperature for 12 h and were studied by means of d. c. electrical resistivity and Infrared spectroscopy. The d.c. electrical resistivity measurements of all the samples were performed on disc shaped pellets using two-probe method. The measurements were carried out in the temperature range 300-800K. The Activation energy deduced from d.c. electrical resistivity showed that paramagnetic region is greater than that of the ferrimagnetic region. Curie temperature T_c deduced from d.c. electrical resistivity data decreases with x, suggesting a decrease in ferrimagnetic behaviour. From IR spectra it is revealed that high frequency band (v₁) lie at around 600 cm^-1 and low frequency band (v₂) around 400 cm^-1. The difference in the values of band position is due to the Fe³⁺-O-Fe²⁺ distances. Using IR data, force constants K₀ and K have been obtained.

2 illus, 2 tables, 16 ref

012449   Ali M Z (Physics Dep, Quaid-i-Azam Campus, Punjab Univ, Lahore, 54590, Pakistan) : Photonic gaps in one-dimensional PBG materials containing dispersive single or bouble negative metamaterials. Asian J Phys 2009, 18(1), 1-6.

The conventional photonic band gap (PBG) materials are characterized by the Bragg gaps. With the experimental nealization of double negative (also known as left handed) and single negative metamaterials, mechanisms other than Bragg reflections can produce photonic gaps in PBG materials. In this article, the origin of these new gaps i.e. the zero-n gap, the zero-φ_eff gap and the angular gaps is briefly discussed. Some of their properties are also described.

4 illus, 30 ref

012448   Algude S G;Lohar K S;Patange S M;Shinde S S; Jadhav S P;Brajdar A A;Gurav S K;Mane D E;Jadhav K M (NO, Adars College, Omerga) : Structural and magnetic properties of Co_0.7Zn_0.3Fe_2-xCr_XO₄ system. Bionano Front 2010, NCANDT(spl), 100-4.

The chromium substituted cobalt zinc ferrite prepared by well know ceramic method were studied at room temperature usmg X-ray diffraction and high field hysteresis field loop technique. The analysis of x-ray diffraction patterns indicates that the samples have single phase cubic spinel structure. The lattice constant initially increases then decrease with concentration of Chromium ion increases. The particle sizes obtained from Scherrer equation lie in the few hundred micro meters. The saturation magnetization and magneton number both are decreasing with increase of chromium concentration x. The decrease in saturation magnetization and magneton number is attributed to the substitution of the Cr^{3+ ions. Curie temperature decrease with increases in Cr content x.}

4 illus, 1 table, 11 ref

011526   Zoliana B;Pachuau Z;Thapa R K (Physics Dep, Govt. Zirtiri Residential Science College, Aizawl-796 001, Email: bzoliana@rediffmail.com) : Application of mathieu potential to calculation of photocurrent from the surface of metals. Sci Vision 2009, 9(4), 183-7.

Mathieu potential have been used for the photoemission calculations from surfaces of ferromagnetic material, Fe (iron), and semiconductor, PbSe (lead selenide). This approach gives a qualitative characterization of surface state photoemission by considering only the surface contribution from the existing bulk-band structure calculations. In this paper, we present the calculations of photocurrent from Fe and PbSe by using the Mathieu potential which defines the crystal potential. The derived initial wave function was used and variation of photocurrent only by those contribution from the surface region defined was calculated. Photocurrent was calculated for values of z_c = -2 a.u. and z_c = -8 a.u. As the width of the surface is 10 a.u. in both the cases, z₀ = -2 a.u. is near the surface-vacuum interface and z₀ = -8 a.u. is towards the surface-bulk interface. We found that at low photon energy range, the metal and the semiconductor under study showed similar trend in the behaviour of photocurrent at a region nearer to edge of the surface.

3 illus, 9 ref

011525   You Y (School of Physics and Electronics, Yancheng Teachers College, Yancheng 224002, Jiangsu, China, Email: yctcyouyuan@163.com) : Radiation from a current sheet at the interface between a conventional medium and anisotropic negative refractive medium. Bull Mater Sci 2009, 32(4), 437-41.

Investigates the radiation from a current sheet at the interface between semi-infinite isotropic positive refractive medium and anisotropic negative refractive medium. The distribution of the electric and magnetic fields in two regions and Poynting vectors associated with propagating and evanescent waves are calculated. The reasons for the singularity of the electric or magnetic field are briefly provided if the waves are evanescent in two media.

19 ref

011524   Yang G;Sheng D Y;Tan J C;Yang Y C;Shen B J (Research Institute of Tech-Physics, College of Science, National Univ of Defense Technology, Changsha City, Hunan Province, P.R. China-410 073) : Cascade protector for hardening electronic devices against high power microwaves. Def Sci J 2009, 59(1), 55-7.

Since the increasing front part of incident microwave pulses may pass through plasma limiler before it generates plasma (the breakdown time of low pressure Xe in plasma limiter is 10 ns), single plasma limiters are not adequate for protecting sensitive electronic components against high power microwaves (HPM). A cascade protector, which consists of a plasma limiter and a PIN limiter in waveguide, is proposed. The numerical results show that under HPM attack (10 GW, 1GHz, and (100 ns pulse width), the microwave power leakage through the cascade protector is about 0.4 W. In the same electromagnetic environment, the power leakage through single plasma limiter is approximate 347 W.

^ssc4 illus, 1 table, 7 ref

011523   Yadav A V;Patil A R;Jamadade V S;Lokhande C D;Fulari V J (Thin Film Physics Laboratory, Physics Dep, Shivaji Univ, Kolhapur-416 004, Email: vijayfulari@gmail.com) : Electrosynthesized hydrophilic iron oxide thin films from aqueous sulphate bath and their supercapacitive performance. Bionano Front 2010, ICLAM(spl), 47-9.

Iron oxide thin films have been successfully prepared from aqueous sulphate bath using electrodeposition method on stainless steel (304) substrate. These films were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM); fourier transform infrared spectroscopy (FTIR) and contact angle measurement. The XRD study revealed the polycrystalline structure of iron oxide film. Porous and nydrophilic surface of iron oxide film was confirmed by SEM and contact angle measurement. The formation of elemental bonds of iron oxide studied using FTIR spectroscopy. The supercapacitive performance of iron oxide film tested using cyclic voltammetry (C-V) technique. The effect of electrolytes, electrolyte concentrations, scan rate and stability of films has been studied. The highest specific capacitance 160 Fg' was observed in 1M NaOH at the voltage scan rate of 20 mVs^-1.

6 illus, 9 ref

011522   Venkatachalam M;Kannan M D;Muthukumarasamy N; Prasanna S;Jaya kumar S;Balasundaraprabhu R;Saroja M (Physics Dep, PSG College of Technology, Coimbatore) : Electron beam deposited CuIn_0.75Ga_0.25Se₂ thin film solar cells. Natn J Technol 2009, 5(4), 77-81.

CIGS bulk with composition of CuIn_0.75Ga_0.25Se₂ has been synthesized by direct reaction of elemental copper, indium, gallium and selenium. CIGS thin films have been deposited onto well-cleaned glass substrates using the prepared bulk by electron beam deposition method. The structural properties of the deposited films have been studied using x-ray diffraction technique. The as-deposited CIGS films have been found to be amorphous in nature. To study the effect of annealing on the structural properties, the films have been annealed in vacuum with a base pressure of 10^{-5 Torr. The x-ray diffractograms of the annealed CIGS films indicated that the films are crystalline with tetragonal chalcopyrite structure. The micro structural parameters like grain size, dislocation density and strain have been evaluated. The chemical constituents present in the deposited CIGS films have been identified using energy dispersive x-ray analysis. The surface topography of the films has been studied using AFM. The thickness of the films has been determined by multiple beam interferometry technique. CIGS based solar cells have been fabricated on molybdenum or ITO coated glass substrates and the efficiencies have been evaluated.}

2 illus, 1 table, 23 ref

011521   Varughese G;Santosh Kumar A;Philp J;Louis G (Physics Dep, Catholicate College, Pathanamthitta-689 648, Email: gvushakoppara@yahoo.co.in) : Anisotropy in elastic properties of lithium sodium sulphate hexahydrate single crystal-an ultrasonic study. Bull Mater Sci 2009, 32(6), 621-6.

The double sulfate family (ABSO₄), where A and B are alkali metal cations, is the object of great interest owing to the complexity and richness of its sequence of phase transition induced by temperature variation. A new sulfate salt characterized by the presence of water molecule in the unit cell with the chemical formula, Li2Na₃(SO₄)2-6H₂O (LSSW), was obtained. The ultrasonic velocity measurement was done with pulse echo overlap technique [PEO]. All the six second order elastic stiffness constants, C₁₁t = C₂₂, C₃₃, C₄₄ = C₁₂, C₁₄, C₁₄ and C₁₃ = C₂₃ are reported for the first time. The anisotropy in the elastic properties of the crystal are well explained by the pictorial representation of the polar plots of phase velocity, slowness, Young's modulus and linear compressibility in a-b and a-c planes.

8 illus, 2 tables, 11 ref

011520   Vaish R;Verma K B R (Materials Research Centre, Indian Institute of Science, Bangalore-560 012, Email: kbrvarma@mrc.iisc.ernet.in) : Influence of seeding on crystallization behaviour of BaNaB₉O₁₅ glasses. Bull Mater Sci 2009, 32(1), 93-8.

Transparent BaNaB₉O₁₅ (BNBO) glasses were fabricated via the conventional melt-quenching technique. X-ray powder diffraction (XRD) followed by differential scanning calorimetric (DSC) studies confirmed the amorphous and glassy nature of the as-quenched samples, respectively. The effect of seeding on the crystallization of BNBO glasses was studied by non-isothermal DSC method and was modeled using the Johnson-Mehl-Avrami and Ozawa equations. The activation energy for seeded glasses decreased with the increase in fraction of crystallization. The values for the onset of crystallization and Avrami exponent were found to be lower for seeded samples which were associated with the heterogeneous nucleation and epitaxial processes.

7 illus, 23 ref

011519   Uthanna S;Madhavi V;Chandra Sekhar M;Nirupama V (Physics Dep, Sri Venkateswara Univ, Tirupati-517 502, Email: uthanna@rediffmail.com) : Substrate bias influenced physical behaviour of magnetron sputtered MoO₃ films. Natn J Technol 2009, 5(4), 66-9.

Thin films of molybdenum oxide were deposited on unheated glass and crystalline silicon substrates using dc magnetron sputtering method by sputtering of molybdenum target in the presence of oxygen and argon gas mixture under various substrate bias voltages in the range 0 to -150 V. The effect of substrate bias voltage on the chemical binding configuration, structure and optical properties was studied. The films formed on unheated substrates were amorphous in nature. The films deposited at -90 V were polycrystalline with coexistence of MoO₃ and MoO_3-x phases. Further increase of substrate bias voltage to -120 V films was polycrystalline with single phase orthorhombic α- phase of MoO₃. The optical band gap of the films increased from 3.03 eV to 3.22 eV and refractive index increased from 2.03 to 2.13 with the increase of substrate bias voltage from 0 to -120 V due to the improvement in the crystallinity and packing density of the firms.

4 illus, 17 ref

011518   Sriramachandran P;Padma D;Kadagalakshmi S; Suriyakala R;Sami P;Shanmugavel R (Physics Dep, VHNSN College, Virudhunagar-626 002, Email: sri_ramnivash@rediffmail.com) : Synthesis and characterization of Cd_1-xZn_xS material by chemical route. Asian J Spectrosc 2009, 13(1-3), 31-4.

The material of configuration Cd_1-x Zn_x S (x varied 0, 0.2, 0.4, 0.6, 0.8, 1) for this study has been prepared by precipitated technique with passing H_2S gas. The powder X-ray diffraction data has been tabulated and indexed. It is confirmed by X-ray diffraction estimation that materials prepared are nano-materials. The presence of functional groups has been confirmed by FTIR analysis.

1 illus, 2 tables, 5 ref

011517   Sinha E;Rout S K (Physics Dep, National Institute of Technology, Rourkela-769 008, Email: elasinha@gmail.com) : Influence of fibre-surface treatment on structural, thermal and mechanical properties of jute fibre and its composite. Bull Mater Sci 2009, 32(1), 65-76.

Jute fibres (Corchorus olitorious), an environmentally and ecologically friendly product, were chemically modified and treated with 5% NaOII solution at room temperature for 2 h, 4 h and 8 h. The above samples were characterized and morphologically analysed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and Instron 1185. Alkali treatment affects the supramolecular structure of the fibre as shown by XRD by improving the degree of crystallinity of the fibre. Surface chemistry of the fibre also altered as depicted by FT-IR studies. This chemical treatment was also found to alter the characteristic of the fibre surface topography as seen by the SEM. From the mechanical single fibre test it was found that the tenacity and modulus of the fibre improved after alkali treatment. This might be due to the improvement in the crystallinity. DSC data demonstrated that the thermal degradation temperature for the cellulose get lowered from 365-26°C to 360-62°C after alkali treatment led to the reduction in fibre thermal stability. Jute fibre reinforced composite were prepared with treated and untreated jute fibre (15 wt%) reinforced unsaturated polyester (UI'E). Effectiveness of these composites was experimentally investigated through the study of the composites by DSC, Instron 1195 for mechanical property of composites, volume fraction of the porosity and hydrophobic finishing of the composite. From the DSC analysis it was found that thermal stability enhanced for treated fibre reinforced composite. This could be due to the resistance offered by the closely packed cellulose chain in combination with the resin. Flexural strength of the composite prepared with 2 h and 4 h alkali treated fibre were found to increase by 3.16% and 9.5%, respectively. Although 8 h treated fibre exhibited maximum strength properties, but the composite prepared with them showed lower strength value. Alkali treatment helped in the development of hydrophobicity and reduction in volume fraction of the porosity. This may be due to the better fibre matrix interface adhesion caused due to the fibre surface treatment by alkali.

8 tables, 5 illus, 28 ref

011516   Shinde S K;Gayakvad K R;Dubal D P;Lokhande C D;Fulari V J (Thin Film Physics Laboratory, Physics Dep, Shivaji Univ, Kolhapur-416 004, Email: vijayfulari@gmail.com) : Chemical synthesis of nanosheet structured copper oxide thin films for supercapacitor application. Bionano Front 2010, ICLAM(spl), 172-3.

Nanosheet structured copper oxide films have been successfully deposited on stainless steel substrates using chemical bath deposition method (CBD). These nanosheet structured copper oxide films were characterized using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and contact angle measurement. The XRD study revealed amorphous nature of films and elemental bonds of copper oxide confirmed by FTIR. SEM images showed multilayer nanosheet like morphology and surface wettability studies suggested hydrophilic surface with water contact angle 53°. The supercapacitive performance of nano sheet structured copper oxide thin films studied using cyclic vottarnmetry technique. The highest specific capacitance 43 Fg^{-1 achieved in 1M Na₂SO₄ electrolyte at the scan rate 20 mVs-1}

5 illus, 7 ref

011515   Shinde N S;Malekar V P;relekar B P;Rath M C; Fulari V J (NO, Karmaveer Bhaurao Patil College, Islampur, Maharashtra) : Modification of structural, optical and surface wettability of antimony sulphide thin films by using electron beam irradiation. Bionano Front 2010, ICLAM(spl), 136-7.

Antimony sulphide (Sb₂S₃) films have been synthesized via an easy and simple electrodeposition process. The Sb₂S₃ thin films have been deposited on to stainless steel and fluorine doped tin oxide (FTO) coated glass substrates, in potentiostatic mode using antimony trichloride (SbCl₃), sodium thiosulphate (Na₂S₂O₃) as a precursor sources and ethylene diamine tetra-acetic acid (EDTA) was used as a complexing agent. The phase structure and morphology of the Sb₂S₃ produces were characterized by XRD, SEM, Optical absorption and Surface wettability. It is observed that the band gap of the films gets red shifted and increase in crystallinity after irradiation. In addition, there is an increase in the grain size of the films due to irradiation, leading to the increase in contact angle.

5 illus, 7 ref

011514   Sharma S (NO, Jaypee Institute of Information Technology Univ, Noida-201 307) : Thermo creep transition in non-homogeneous thick-walled rotating cylinders. Def Sci J 2009, 59(1), 30-6.

Creep stresses have been derived using transition theory. The results for the combined effects of angular speed and temperature are calculated and depicted graphically. It has been observed that a cylinder made of less compressible material at the internal surface and highly compressible at the outer surface is on the safer side of the design for different values of NΩ and temperature as compared to highly compressible material al the internal surface and less compressible at the outer surface.

4 illus, 1 table, 11 ref

011513   Seddigi Z S (Chemistry Dep, Umm Al-Qura Univ, Makkah, Saudi Arabia, Email: zsseddigi@uqu.edu.sa) : Solid state photoluminescence behavior of CuBr(C₁₂H₈N₂)(C₂₀H₂₀NP) and CuBr(C₁₂H₈N₂)(C₂₁H₂₁P). C₃H₇No. Asian J Spectrosc 2009, 13(1-3), 1-7.

Two newly prepared mixed-Hgand complexes have shown strong solid state photoluminescent behavior. The complexes are CuBr(C₁₂H₈N₂)(C₂₀H₂₀NP) and CuBr(C₁₂H₈N₂)(C₂H₂P). C₃H₇NO. To understand the nature of the solid state photoluminescence behavior, ab initio based calculations were employed. These calculations allowed the identification of major atomic contributions to HOMO, LUMO and LUMO+n orbitals. Contrary to common excitation mechanism in pure Cu(I) complexes exhibiting MLCT excitation mechanism, these bromide-based copper(I) complexes exhibit excitation mechanism of the type LMCT as indicated by ab initio calculations. The introduction of bromide into the system reverses the usual excitation mechanism.

2 illus, 2 tables, 15 ref

011512   Sebastian S;Manuel A;Regimole P R; Syamalakumari B;Paulose P I (Physics Dep, Research Centre, Maharajas College, Ernakulam, Kochi-11, Email: pipaul2006@yahoo.co.in) : Spectroscopic studies of Nd<. Asian J Spectrosc 2009, 13(1-3), 21-9.

The silica gel matrixes doped with varying concentrations of Nd^{3+ ion were prepared by the sol - gel method. The samples were characterized by XRD and TGA. The absorption and luminescence properties of silica glass doped with different Nd3+ ion concentrations were studied. The absorption peaks are found to increase in intensity with the rare earth ion concentration. Various electronic transitions in Nd3+ were assigned by using the recorded absorption spectra. Direct and indirect band gap energy of Nd3+ doped amorphous semiconductor are determined. From the data available in the optical absorption spectra, various spectroscopic parameters such as electric dipole strength, oscillator strength and JO parameters of Nd3are derived. The calculated values of JO parameters are then utilized in evaluating the radiative parameters such as radiative transition probability (Arad), radiative life time (τtrad), fluorescence branching ratio (β) and the integrated absorption cross- section (δ) for stimulated emission. The branching ratio of the luminous transition originating from the F_3/2 level characterized the lasing power and (β) with a value greater than 50% become a potential laser emission. The Nd3+ ion in an amorphous material shows lasing properties.}

4 illus, 3 tables, 16 ref

011511   Sarmah K;Sarma R (Physics Dep, Gauhati Univ, Guwahati-781 014, Email: ks_guphys@rediffmail.com) : Mobility activation in thermally deposited CdSe thin films. Bull Mater Sci 2009, 32(4), 369-73.

Effect of illumination on mobility has been studied from the photocurrent decay characteristics of thermally evaporated CdSe thin films deposited on suitably cleaned glass substrate held at elevated substrate temperatures. The study indicates that the mobilities of the carriers of different trap levels are activated due to the energy of incident illumination, which results in the existence of two distinct trap levels. In each trap depth the energy of the trap increases linearly. It infers that there is a linear distribution of traps of different energies below the conduction band.

5 illus, 1 table, 19 ref

011510   Sapnar K B;Sisodia V;Ghule L A;Garadkar K M; Dahiwale S;Dhole S D;Bhoraskar V N (Physics Dep, Microtron Accelerator Laboratory, Pune Univ, Pune, Email: sanjay@physics.unipune.ernet.in) : Effect of 6 MeV electron irradiation on ZnO nanoparticles synthesized by microwave method. Bionano Front 2010, ICLAM(spl), 124-9.

The nanoparticles of zinc-oxide (ZnO) were synthesized by microwave method followed by annealing at 60°C for the three hours. After characterization with XRD, SEM and UV methods, it was observed that the synthesized particles were of ZnO with size 46 nm. These nanoparticles were irradiated with 6 MeV electrons made available from the Race-Track Microtron. The electron fluence was varied from 1.5x10^{15 to 2.5 x1015 eV cm2. The average particle size reduced from 46 nm to 15 nm at an electron fluence of 2.5 x1015 e I cm2. As revealed from the UV measurements, the band gap of ZnO increased from the virgin value of 3,29 eV to 3.42 eV for at an electron fluence of 2.5 x1015 e- / cm2. The results indicate that by electron irradiation, the particle size of ZnO can be tailored to suit for the applications in the field of photovoltaics and photo cells.}

9 illus, 40 ref

011509   Sanosh K P;Chu M C;Balakrishnan A;Kim T N;Cho S J (Meterology for Emerging Technology Div, Korea Research Institute of Standards and Science, 1 Doryong-Dong, Yuseong-Gu, Daejeon 305-340, Republic of Korea, Email: the_krecian@yahoo.com) : Preparation and characterization of nano-hydroxyapatite powder using sol-gel technique. Bull Mater Sci 2009, 32(5), 465-70.

Hydroxyapatite (HA) nano powders (20-60 run) were synthesized using a sol-gel route with calcium nitrate and phosphoric acid as calcium and phosphorus precursors, respectively. Double distilled water was used as a diluting media for HA sol preparation and ammonia was used to adjust the pH. After aging, the HA gel was dried at 65°C and calcined to different temperatures ranging from 200-800°C. The dried and calcined powders were characterized for phase composition using X-ray diffractometry, elemental dispersive X-ray and Fourier transform infra-red spectroscopy. The particle size and morphology were studied using transmission electron microscopy. Calcination revealed HA nano powders of increased particle size and crystallinity with increase in temperature. For all calcinations temperatures, the particle size distribution analysis of HA powders showed skewed distribution plot. At temperature of 700°C and above, formation of CaO was noticed which was attributed to phosphorous volatilization. This study showed that high purity HA with varying degrees of crystallinity could be obtained using this simple technique.

7 illus, 1 table, 36 ref

011508   Sanap V B;Pawar B H;Kawar S S;Suryawanshi A D (P.G. Dep of Physics, S.G.B. Amravati Univ, Amravati-444 605, Email: vbsanap@rediffmail.com) : Structural and optical study of effect of cadmium sources on nanocrystalline CdS thin films. Bionano Front 2010, ICLAM(spl), 71-3.

The effect of various cadmium sources on CdS thin films deposited by chemical bath deposition technique was investigated in this paper. Cadmium iodide, cadmium chloride, cadmium nitrate and cadmium sulfate have been used as a cadmium source. The structural and optical properties have been studied. The asdeposited CdS films were characterized by XRD, SEM and spectrophotometer. All the CdS films have single cubic structure. The films have averagely 75% transmittance, 15% absorbance and 4% reflectance towards the VIS-Near IR region.

2 illus, 1 table, 13 ref

011507   Ravangave L S;Hiswankar S U;Munde B S; Suraywanshi A D;Pawar B H (Physics Dep, Sant Gadge Baba College, Loha, Dist. Nanded, Maharashtra) : Comparative study of bulk and nano LaF₃: EU synthesized by co-precipitation method. Bionano Front 2010, ICLAM(spl), 90-2.

The LaF₃:Eu nano particles are synthesized by the co-precipitation method and LaF3:Eu bulk was prepared by simple precipitation method. The LaF₃:Eu nanoparticles' are roughly cylindrical shaped and the average size is 24.60 rtm. These nanoparticles were characterised using X-ray diffraction, transmission electron microscopy and photoluminescence spectra.

5 illus, 1 table, 5 ref

011506   Raghavender A T;Jadhav K M (Electronics and Communication Engineering Dep, Nishitha College of Engineering and Technology, R.R. District-501 559, Email: raghavi9@gmail.com) : Dielectric properties of Al-substituted Co ferrite nanoparticles. Bull Mater Sci 2009, 32(6), 575-8.

A series of polycrystalline spinel ferrites with composition, CoFe₂Al_xO₄ (θ< x < 1), have been synthesized by sol-gel method. The effect of Al-substitution on structural and dielectric properties is reported in this paper. X-ray diffraction analysis revealed the nanocrystalline nature in the prepared ferrite samples. The particle size, D, decreases with increase in Al-content. The lattice parameter, a and X-ray density, d_x, decreased with increase in Al-content. The dielectric properties for all the samples have been studied as a function of frequency in the range 100 Hz-10 MHz. Dielectric properties such as dielectric constant, ε, dielectric loss, ε and dielectric loss tangent, tan δ, have been studied for nanocrystalline ferrite samples as a function of frequency. The dielectric constant and dielectric loss obtained for the nanocrystalline ferrites proposed by this technique possess lower value than that of the ferrites prepared by other methods for the same composition. The low dielectric behaviour makes ferrite materials useful in high frequency applications.

4 illus, 1 table, 16 ref

011505   Qaiser D;Zafar S;Khan M S;Singh R D;Khan Z H (Physics Dep, Jamia Millia Islamia, New Delhi-110 025, Email: shahid.ph@jmi.ac.in) : Laser induced fluorescence of fullerene C₇₀-quinizarine complex and its fret study. Bionano Front 2010, ICLAM(spl), 11-13.

The complex formation between Fullerene C₇₀ (acceptor) and 1,4-dihydroxy-9,10-anthraquinone (Quinizarine) as donor molecule has been studied by using laser induced fluorescence. The effect of concentration on Forster's resonance energy transfer (FRET) has been studied in the visible region by changing the acceptor concentration for the fixed value of the donor concentration. The efficiency of energy transfer was found to be first increasing and then decreasing after certain concentration.

5 illus, 1 table, 13 ref

011504   Pusawale S N;Deshmukh P R;Jamadade V S;Gurav K V;Lokhande C D (Thin Film Physics Laboratory, Physics Dep, Shivaji Univ, Kolhapur-416 004, Email: l_chandrakant@yahoo.com) : Synthesis and electrochemical characterization of hydrous SnO₂ for supercapacitors. Bionano Front 2010, ICLAM(spl), 44-5.

In the invention we have successfully deposited hydrous SnO₂ thin films by modified chemical bath deposition method (M-CBD) at room temperature using SnCl₂ as precursor solution. The usefulness of chemically deposited hydrous SnO₂ for supercapacitors is proposed for the first time. The as deposited films were characterized for their structural and surface morphological studies by X-ray diffraction (XRD) and scanning electron microscopy (SEM) technique. From the XRD studies hydrous nature of SnO₂ thin films is revealed. SEM image showed the formation of porous and non uniform agglomerates. Fourier transform infrared spectroscopy (FTIR) confirmed the formation of Sn-O phase with characteristic absorption peak at 579 cm^{-1, the strong absorption peak at 1630 cm-1 corresponds to O-H stretching vibrations confirms the hydous nature of the SnO₂ thin films. Further the electrochemical properties of the films were studied using cyclic voltammetry technique using different aqueous electrolytes such as NaOH, KOH, Na₂SO₄, KCI etc. The effect of electrolyte concentration and scan rate on the specific capacitance of hydrous SnO₂ electrodes has been studied. The highest specific capacitance of 20 Fg-1 is achieved for hydrous SnO₂ electrode in 0.5 M Na₂SO₄ electrolyte at the 5 mVs-1 voltage scan rate.}

6 illus, 6 ref

011503   Praveen Kumar P;Manivannan V;Sagayaraj P; Madhavan J (Physics Dep, Loyola College, Chennai-600 034, Email: jmadhavang@yahoo.com) : Growth and characterization of pure and doped NLO L-arginine acetate single crystals. Bull Mater Sci 2009, 32(4), 431-5.

Single crystals of pure, Cu^{2+ and Mg2+ doped L-arginine acetate (LAA) were grown successfully by slow evaporation technique. In order to improve the device characteristics of LAA crystals, metal dopants of Cu2+ and Mg2+ were incorporated into the parent crystals. The grown pure and doped crystals were confirmed by X-ray powder diffraction studies. The pure and doped crystals were characterized by Fourier transform Raman (FT-Raman) and thermal studies. Absorptions of these grown crystals were analysed using UV-Vis-NIR studies, and it was found that these crystals possess minimum absorption in the entire visible region. Nonlinear optical studies of pure and doped crystals were carried out and it reveals that the dopants have increased the efficiency of LAA crystals.}

011502   Pratap A;Lilly Shanker Rao T;Patel K;Chawda M (Applied Physics Dep, Faculty of Technology and Engineering, The M.S. Univ of Baroda, Vadodara-390 001, Email: apratapmsu@yahoo.com) : Kinetics of crystallization of a fe-based multicomponent amorphous alloy. Bull Mater Sci 2009, 32(5), 527-9.

The Fe-based multicomponent amorphous alloys (also referred to as metallic glasses) are known to exhibit soft magnetic properties and, it makes them important for many technological applications. However, metallic glasses are in a thermodynamically metastable state and in case of high temperature operating conditions, the thermally activated crystallization would be detrimental to their magnetic properties. The study of crystallization kinetics of metallic glasses gives useful insight about its thermal stability. In the present work, crystallization study of Fe₆₇Co₁₈B₁₄Si₁ (2605CO) metallic glass has been carried out using differential scanning calorimetry (DSC) technique. Mossbauer study has also been undertaken to know the phases formed during the crystallization process. The alloy shows two-stage crystallization. The activation energy has been derived using the Kissinger method. It is found to be equal to 220 kj/mol and 349 kj/mol for the first and second crystallization peaks, respectively. The Mossbauer study indicates the formation of a-(Fe, Co) and (Fe, Co)₃,B phases in the alloy.

3 illus, 14 ref

011501   Prakash S;Rajasingh S;Rajesh S (Physics Dep, VHNSN College, Virudhunagar, Tamilnadu-626 001, Email: mms_prakash@yahoo.co.in) : Ab initio study of 7-methoxyl-4'-hydroxyisoflavone. Asian J Spectrosc 2009, 13(1-3), 39-40.

The molecular structure of 7-methoxyl-4'-hydroxyisoflavone has been optimized by using ab initio calculation at the Hartree-Fock level theory on the basis set 6-31G(d,p). The optimized geometrical parameters were compared with the experimental values. The ab initio optimized structure was used as the starting point for the further vibrational frequencies calculation and theoretical assignments were thus obtained.

2 tables, 8 ref

011500   Pawar P P;Chaudhari V A;Bichile G K (Physics Dep, Dr. B.A.M. Univ, Aurangabad-431 004, Email: pravina.pawar@yahoo.com ) : Synthesis and characterization of nano thin films. Bionano Front 2010, ICLAM(spl), 76-80.

Describes the various synthesis methods of depositing nano thin films using chemical film deposition methods. Thin films can be deposited by using various methods. The methods can be brodly divided in to physical and chemical routes. In this paper various methods under second category have been briefly discussed. Chemical methods such as conventional chemical vapour deposition (CVD), Laser CVD, metal oregano chemical vapour deposition (MOCVD) and plasma enhanced chemical vapour deposition have been widely used. Liquid phase chemical techniques include electro deposition, chemical bath deposition, anodization, spray pyrolysis etc.

5 illus, 10 ref

011499   Patil V A;Patil A R;Choi J W;Yoon S J (Thin Film Materials Research Centre, Korea Institute of Science and Technology, Seoul 136-791) : Fabrication and characterization of LICOO₂ thin film cathode for rechargeable lithium batteries. Bionano Front 2010, ICLAM(spl), 162-3.

There is an increasing need for new batteries with lightweight, long-life, high energy density because of the recent developments of microelectronic devices and integrated optoelectronic circuits. One approach to fulfilling this need is to develop all solid-state thin film lithium based batteries. LiCoO₂ has been commercialized as the cathode material in lithium secondary battery due to its advantages in high specific capacity, high operating voltage, and long cycle life. Thin film LiCoO₂ has recently been used as a cathode in microbatteries that may potentially supply power for microelectronics such as on-chip applications. The structure of layered LiCoO₂ has rhombohedral symmetry and belongs to the space group R3m, and is ideally suited to accommodate large changes in Li concentration. This crystal structure consists of close-packed oxygen ion layers separated by alternating layers of Li and cobalt ions. In a commercial cell, the LiCoO₂ cathode is typically charged to 4.2V with respect to Li metal (Li_0.5CoO₂), yielding a specific capacity of about 140 mAh/g. Due to this high energy storage capacity, LiCoO₂ based rechargeable batteries are now widely used in portable electronics such as laptop computers and cellular telephones. In the fabrication of LiCoO₂ thin films, formation of the layered structure is known to be crucial for obtaining a good rechargeability of the cells. The low-temperature synthesis of LiCoO₂ provides small grain size and high surface area that greatly improved cell performance because of better capacity, polarization, and cell reversibility. Pulsed laser deposition (PLD) is becoming a popular tool to prepare thin films of high-temperature superconductors, ferroelectric and ferromagnetic materials, etc. with preferred orientation. In this study, crack free LiCoO₂ thin films have been prepared by PLD. The structural characterizations of these films have been carried out by various techniques as X-ray diffraction (XRD), and electron scanning microscopy (SEM). We have studied the electrochemical behavior of LiCoO₂ thin films by investigating the cyclic voltammetry and the chargedischarge profile in lithium microbatteries.

3 illus, 6 ref

011498   Patil S S;Pawar P H (Thin Film Research Laboratory, Physics Dep, Zulal Bhilajirao Patil College, Deopur, Dhule, Maharashtra, Email: sunil1441@rediffmail.com) : Structural and optical properties of thermally evaporated CdTe thin films. Bionano Front 2010, ICLAM(spl), 141-4.

CdTe thin films of different thicknesses on glass substrates have been prepared by thermal evaporation technique at room temperature in vacuum (=10^{-6 Torr). The selected samples were annealed at 573 K for 30 min. in vacuum (≈ 10-5 Torr). The X-ray diffraction (XRD) patterns of the two CdTe samples with thickness 2000 and 4000 were recorded by X-ray diffractometer. The XRD patterns exhibits polycrystalline nature which suggests that these CdTe films are of zinc blende structure with a preferential orientation along the (111) plane of cubic phase. The crystallite size (D), dislocation density (ε) and strain (ε) were calculated. The lattice parameter values obtained are a ≈ 6.47 and a ≈ 6.50. The reflectance and transmittance spectra of these samples were recorded using double beam spectrophotometer in the spectral range of 2002700 nm. The fundamental optical parameters like absorption coefficient (a) and band gap are calculated from the transmission spectra. The possible optical transition in these films is found to be direct and allowed. The refractive indices (n) and extinction coefficients (k) have been evaluated from the reflectance data.}

4 illus, 2 table,s 29 ref

011497   Patil S;Mane D R;Kadam R H;Kadam A B;More S S (Material Science Research Lab, Shrikrishna Mahavidyalaya Gunjoti, Osmanabad, Maharashtra, Email: ram111612@yahoo.co.in) : XRD examination of Sol-Gel synthesized LI_0.5FE_2.5-XMIN_XO₄. Bionano Front 2010, ICLAM(spl), 103-5.

Li_0.5Fe_2.5-xMn_xO₄ ferrites were prepared by solgel method. The ferrite samples synthesized by solgel auto combustion method using nitrates of respective metal ions. The synthesized samples were annealed at 600 °C for 4 h. X-ray diffraction studies of the prepared material show that the particle size lies in the nano range, with the smallest crystallite size being around 25 nm. An analysis of X-ray diffraction patterns reveals the formation of single phase cubic spinel structure. The crystal lattice constant advances gradually with increasing Mn content x. X-ray density, bulk density and porosity decreases with Mn substitution. Hopping length increases with increase in Mn content x.

5 illus, 1 table, 20 ref

011496   Patil S D;Jali V M;Anavekar R V (Physics Dep, Gulbarga Univ, Gulbarga-585 106, Email: vmjali@rediffmail.com) : Elastic properties of Na₂O-ZnO-ZnF₂-B₂O₃ oxyfluoride glasses. Bull Mater Sci 2009, 32(6), 597-601.

Elastic properties of Na₂O-ZnO-ZnF₂-B₂O₃ oxyfluoride glasses with different ZnF₂ concentrations have been investigated using ultrasonic velocity measurements at room temperature, at a frequency of 10 MHz. Glasses prepared by melt quenching method were suitably polished for the ultrasonic velocity measurements using pulse-echo superposition method. Various elastic moduli have been calculated and their compositional dependence has been examined. The compositional dependence of elastic moduli with the concentration of ZnF₂ shows decrease in the moduli initially, with further increase in ZnF₂ the moduli sharply increases and then again tend to decrease when ZnF₂ concentration is 20mol%. The values of Poisson's ratio lie in the range of 0-24-0-30, which is typical to covalent bonded network. The variation of 60 with ZnF₂ indicates complex behaviour of the glass network. The results have been analysed in view of the modified borate glass network. Addition of ZnF₂ into the pure glass seems to influence the borate network by replacement of B-O-B linkages with B-O-Zn.

6 illus, 1 table, 16 ref