013584   Alfred Cecil Raj A;Sinthiya A;Jebas S R; Bheeter S R (Physics Dep, St. Joseph's College, Trichy-620 002, Email: sac63raj@gmail.com) : Synthesis and characterization of tetrakis (4 aminpyridine - _kN<. Bull pure appl Sci-Sect D 2009, 28(2), 121-5.

The blue [CuCl₂ (C₅H₆N₂)₄] H₂O crystals have been synthesized by the slow evaporation technique. The grown crystals have been characterized using UV-visible spectrum, FTIR spectrum, Differential Thermal Analysis (DTA) and Thermo Gravimetric Analysis (TGA) techniques. The results show that the as-grown crystals were crystallized and indexed in a triclinic system with octahedral geometry. The crystal is in good stability upto 210°C and melts congruently at 245°C. The frequencies of the vibration modes of the crystal were reported from measurements of the infrared spectrum.

4 illus, 1 table, 6 ref

013583   Al-Adel F F;Dastageer M A;Bakhtiari I A (Physics Dep, King Fahd Univ of Petroleum and Minerals, P.O. Box 732, Dhahran 31261, Email: ffdel@kfupm.edu.sa) : Enhancement of detectability limits of NO₃ in deionized water by laser raman spectroscopy. Asian J Spectrosc 2009, 13(4), 101-4.

The nickel nitrate - deionized water system has been studied using laser Raman spectroscopy covering a wide range of ppm values. The intensity of the NO₃ peak observed at around 1040 cm^-1 was calculated carefully, and its changes with the concentration of NO₃ was monitored over a wide range of ppm values. Despite the detectabilty limitations of our small and simple system, our data shows that following this peak can be used to estimate quite accurately the level of infiltration of nitrate in water. Example of our method of calculating the intensity of the 1040 NO₃ peak is shown before presenting our complete data. Results found by other authors are also considered.

3 illus, 11 ref

013582   Aksoy A;Khiari F Z (Physics Dep, Energy Research Center, King Fahd Univ of Petroleum and Minerals, Dhahran 31261, Saudi Arabia, Email: aaksoy@kfupm.edu.sa) : Oil condition monitoring using 14 MeV neutron activation analysis. Asian J Spectrosc 2009, 13(4), 67-74.

The 14 MeV Neutron Activation Analysis (NAA) spectrometry at KFUPM was used to study degradation of two types of turbine oils while in service in steam-turbine compressors operating in parallel at a local plant. The study was carried out to track total oxygen content of the oils and to compare total oxygen with other condition monitoring tests over a one-year service span. Total oxygen content was measured in both new and used oil samples. The results of 14 MeV NAA were compared with those of the RBOT and relative oxidation methods, which measure oxidation resistance in turbine oils and the concentration of oxidation products, respectively. Total oxygen as determined by NAA was found to bear a linear relationship with relative oxidation and a logarithmic relationship with RBOT.

3 illus, 4 tables, 13 ref

013581   Acevedo R;Soto-Bubert A;Valerio M E G;Strek W (Facultad de Ingenieria, Universidad Mayor, Avenida Manuel Montt. 267. Santiago-Chile, Email: roberto.acevedollanos@gmail.com) : Theory of interaction potentials in ionic crystals: an application to the thermodynamics of lanthanide type crystals. Asian J Spectrosc 2009, 13(4), 43-65.

A rather complete and informative analysis of the intermolecular and intramolecular potentials is put forward with reference to the lanthanide type systems, such as Cs₂ NaLnF₆ Cs₂ NaLn F₆ Cs₂ NaLnBr₆ Rb₂ NaLnF₆ and Cs₂ KLnF₆ in the Fm3m space group. The current study is focused to the trivalent lanthanide ions, characterized by atomic numbers in the atomic number interval: 57 ≤ Z ≤ 71. A particular situation occurs in both extreme of the series, say for ₅₇ La : [₅₄ Xe]5d¹ 6s² and ₇₁ Lu : [₅₄ Xe] 4f¹⁴ 5d¹ 6s² respectively. The La⁺³ ion. behaves as pseudo noble gas whereas Lu⁺³ shows a fully occupied 4f shell. A different situation occurs for the thirteen trivalent lanthanide ions, moving along the series from Ce⁺³ to Yb⁺³ for these ions the 4f shell is not fully occupied and therefore the physical and chemical properties are indeed, somehow challenging and interesting to examine using structural, spcctroscopic and theoretical methods and model calculations. In this current research work, we have elaborated some physical models and carried out a substantial amount of calculations, so as to estimate the retieular energy and also, employing a thermodynamic Born-Haber cycle, we have been able to make some sound predictions and numerical estimate of heat of formations for the above series of lanthanide type crystals. The calculated energy values associated with these observables seems to be most reasonable, and these follow the expected trends, as may be anticipated from theoretical and experimental grounds. Both, the advantages and disadvantages of the current model calculations, have been tested against other previous calculations performed. Some convergence tests as well as some master equations are employed to account for the various contributions to the total energy. The Born-Mayer-Buckingham potential is carefully examined with reference to these lanthanide type crystals. Finally but not at last, the most likely sources for improvement are carefully discussed in this work.

13 tables, 47 ref

012512   Yadav S;Bandyopadhyay A K (NO, Natonal Physical Laboratory, New Delhi-110 012, Email: syadav@mail.nplindia.in) : Evaluation of laboratory performance through interlaboratory comparison. MAPAN 2009, 24(2), 125-38.

Reports the performance of the calibration results obtained by 21 laboratories using digital pressure calibrator as an artifact in the pressure range 7-70 MPa. National Physical Laboratory (NPLI), New Delhi has coordinated this programme and also acted as a reference laboratory. The program started in May, 2006 and completed during May, 2008. The comparison was carried out at 10 equally spaced pressure points i.e. 7, 14, 21, 28, 35, 42, 49, 56, 63 and 70 MPa throughout the entire pressure range of 7 - 70 MPa. The calibration results thus obtained were analyzed as per ISO/ IEC GUM document. The 92.7% measurement results are found in agreement with the results of NPLI. The relative deviations between laboratories values and reference values are well within the 0.05% for 123 measurement points, 0.1% for 162 measurement points and 0.25% for 177 measurement points. The difference of the laboratories values with reference values are found almost well within the uncertainty band of the reference values at 68.0% measurement results, within their reported expanded uncertainty band at 81.5% measurement results and within the combined expanded measurement uncertainty band at 92.7 % measurement results. Overall, the results are considered to be reasonably good being the first proficiency testing for most of the participating laboratories.

5 illus, 6 tables, 26 ref

012511   Tiwari S;Srivastava S;Tandom P;Renu Singh; Uttam K N (Saha's Spectroscopy Laboratory, Physics Dep, Allahabad Univ, Allahabad-211 002, Email: kailash.utam@rediffmail.com) : Thermodynamical quantities of germanium and silicon diatomic molecules (GeO₃, GeS, GeSe, GeTe, SiC, SiN, SiO and SiS) from spectroscopic data. Asian J Phys 2009, 18(1), 121-6.

Thermodynamical quantities of germanium and silicon diatomic molecules (GeO, GeS, GeSe, GeTe, SiC, SiN, SiO & SiS) in the temperature range 100-2200 K have been calculated from spectroscopic data using partition function theory. The results have been discussed in terms of molecular motion.

3 tables, 18 ref

012510   Tirmali P M;Khairnar A G;Chandwadkar R;Wagh B;Mahajan A M (Electronics Dep, North Maharastra Univ, Jalgaon-425 001, Email: ammahajan@mmu.ac.in) : Optical properties of ceria thin films deposited by spray pyrolysis technique. Bionano Front 2010, NCANDT(spl), 198-200.

Cerium dioxide (CeO₂) thin films have drawned considerable attention because of their high transparency in the visible and near IR region with wide range of applications. Spray pyrolysis technique found to be suitable for the deposition of Cerium dioxide thin films. In the present study, the thin films were deposited using Cerium chloride hepthahydrate (CeCl₃.7H₂O) diluted in alcohol and water in the ratio of 3:1 as precursor material on glass substrate. Solution with different molar concentrations of 0.025 M and 0.05 M were prepared. The films deposited at low temperatures presented cracks that tend to disappear with the increase of the deposition temperature. The optical properties of the film were investigated. The properties of the films are strongly affected by the deposition parameters viz. substrate temperature, pressure, concentration of solution etc. The films deposited at 400°C presented high optical transmittance values reaching up to 90% (in the visible and infrared range) but absorbed in the UV range. The ability of cerium-doped glass to block out UV light is utilized in the manufacturing of medical glassware and aerospace windows.

1 illus, 1 table, 9 ref

012509   Tidar A L;Kamble S P;Sharma B R;Patil S S; Khirade P W;Mehrotra S C (Physics Dep, Dr. B.A.M. Univ Aurangabad, Maharashtra) : Static dielectric constant, refractive index and density measurements in binary mixture of N, N-dimethylacetamide with 2-butoxyethanol at 300K. Bionano Front 2010, NCANDT(spl), 120-5.

Static dielectric constants (ε_s), refractive indices (n), densities (ρ), at room temperature (300K), of binary mixtures of N, N-Dimethylacetamide (DMA) with 2-Butoxyethanol (2-BE), are reported. The Static dielectric deviations (Δε), refractive indices deviations (Δn), molar refractions (R_m), excess molar volumes (V^E) and excess molar refractions (ΔR_m) were calculated from the experimental data. The results are discussed in terms of intermolecular interactions. The result also shows that the mean molar polarizability (α) in binary mixture decreases as the concentration of DMA increases.

6 illus, 4 tables, 11 ref

012508   Sutar M M;Kokare S R (NO, S.M. Dr. Bapuji Salunkhe College, Miraj, Email: smilind20066@rediffmail.com) : Synthesis and structural studies of lanthanum doped barium titanate for microwave applications. Bionano Front 2010, NCANDT(spl), 126-30.

BaTiO₃ is the most widely used ferroelectric material, and even six decade after its discovery, it is the most important multilayer ceramic dielectric. The objective of this work is to achieve the combined effect of displacer and very high impedance material for microwave applications we opted to synthesize and investigate the BaLa₂Ti₃O₁₀ (BLT) composition. As the method of synthesis plays an important role in its properties. The BLT is synthesized by hydroxide Co-precipitation method. Structural parameter for samples proves that the material is of single phase and tetragonal in structure. The dielectric measurements were performed on BLT ceramic in the temperature region of 30-250° C (i.e. up to transition temperature). This variation shows that the transition temperature remains same but improvement in the dielectric constant suggests that the material could be used for the microwave application. Practically material shows very high DC electrical resistance and vacancy mechanism dominates at higher temperature, like other ferroelectric ceramics.

3 illus, 2 tabels, 6 ref

012507   Song H W;Choi I M;Woo S Y (Mechanical Metrology Group, Korea Research Institute of Standards and Science, Republic of Korea, Email: sywoo.kriss.re.kr) : Extended usage of pressure balance down to a few pa. MAPAN 2009, 24(2), 119-24.

Discusses an extended usage of conventional pressure balances for measurements of pressure down to a few Pa. Generally pressure balances are widely used as pressure standards but they have a major disadvantage, that is, their inability to operate at pressures below a limit determined by the mass of floating elements. This limit is typically around 5 kPa. Several approaches have been tried to reduce this minimum operating pressure, including a tilting piston method, a low-mass piston method, and a variable bell-jar pressure method and so on. Using a variable bell-jar pressure method, authors investigated the lowest usable pressure limit. The experiments show that around 5 Pa is the low pressure limit within the required uncertainty.

2 illus, 2 tables, 4 ref

012506   Shirsath S E;Dorik R G;Pandit A A;Shengule D R;Shukla S J;Jadhav K M (Physics Dep, Dr.B.A.M. Univ, Aurangabad-431 004) : Effect of Zn<. Bionano Front 2010, NCANDT(spl), 231-6.

Zn substituted Ni-ferrites (Ni_1-xZn_xFe₂O₄ where x = 0, 0,2, 0.4, 0.6, 0.8 and 1.0) were prepared using the standard solid state reaction. The crystallogrphic nature of the prepared samples was characterized by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). Lattice constant found to decrease with increase in Zn content x. Porosity decreases from 8.01 to 2.26 whereas bulk density increases from 4.88 - 5.11 gm/cm³ with increases in Zn content x. Magnetization increases upto x = 0.4 and then it decreases with further increases in Zn content. Coercivity decreases from 99 - 20 Oe. The decrease in magnetic parameters are associated with weakening in A-B interaction.

4 illus, 1 table, 22 ref

012505   Shinde S S (Physics Dep, A.S.C. College, Naldurg-413 602, Email: sureshshinde186@gmail.com) : Magnetic behaviour of the spinel system Co_1.4-xZn_xSi_0.4Fe_1.2O₄. Bionano Front 2010, NCANDT(spl), 27-31.

The structural and magnetic properties of the Co_1.4 Zn_xSi_0.4Fe_1.2O₄ system with x = 0.0 to 0.6 has been studied by means of X - ray diffraction, magnetization and a.c. susceptibility measurements. From the present results it appears that the lattice constant increases with increases in Zn content. Variation of magnetic moment per formula unit (n_B) with Zn concentration is explained on the basis of localized canting approach (LCS ). Variation of a.c susceptibility indicates that the system contains MD particles and Curie temperature is found to decrease with increase in Zn concentration.

4 illus, 1 table, 17 ref

012504   Shinde S;Jadhav K M;Kulkarni A;Gadre S;Jadhav M (Vivekanand Arts, Sardar Dalipsingh Commerce & Science College, Aurangabad, Maharashtra, Email: sangtamawal@gmail.com) : Improve the performance and capacity of mangetic storage devices through nanomaterials. Bionano Front 2010, NCANDT(spl), 201-7.

Presents use of nanotechnology to-store data on magnetic devices. Expresssed study of nanostructure material used to stroe data on magnetic storage devices.

4 illus, 17 ref

012503   Shimbare S S;Tayade K D;Sabale M C (Physics Dep, Jijamata Mahavidyalaya, Buldana Dist. Buldana, Maharashtra) : Electrical study of the zinc substituted nickel-lead ferrites. Bionano Front 2010, NCANDT(spl), 20-2.

The electrical properties of Zn^s+ substituted Ni-Pb femes having general chemical formula Ni _{1.25 x}Zn_xPb_0.25Fe_1.5O₄ (where x - 0, 0.1, 0.2, 0.3, 0.4 and 0.5) were prepared by double sintering method. XRD patterns of all the samples confirmed the single-phase cubic spinal structure formation. Variation of A.C. resistivity with temperature is studied in the range 35°C to 55°C. The electrical behavior of the resistively of all the samples can be explained on the basis of electron hopping and current due to electrons in the conduction band. It has been observed that with increase in Zn2+ content (x), there is no significant variation in the temperature at which maximum resistivity is observed.

2 illus, 1 table, 10 ref

012502   Sharma A K;Haridas R N;Patil A V;Bhonsle R V (Space Science Div, Shivaji Univ, Kolhapur, Email: aks_phy@yahoo.co.in ) : Study of ULF/VLF magnetic field fluctuations associated with moderate earthquakes by using induction coil magnetometer at Kolhapur (16.7<. Asian J chem envir Res 2008, 1(2-3), 22-7.

Three axis induction type magnetic receiving system was installed at Shivaji University, Kolhapur (16.7°N, 74.25°E). We have a continuous record of ULF signal in the frequency ranging from 0.01 Hz to 30 Hz. In the present investigation changes in the magnetic field before, during and after few hours of earthquake are reported. Preliminary results about the ultra low frequency response to these events are discussed. The present paper focused on the data of moderate earthquakes, which occurred in the Koyna -Warna region (4 < M < 5).

10 illus, 17 ref

012501   Prasad L;Pandey M K; Sandeep Kumar (Physics Dep, M.B. Govt. (P.G.) College Haldwani, Nainital-263 141, Email: lprasad@iucaa.ernet.in) : On the conversion of phase-mixed alfven wave energy into thermal energy. Asian J Phys 2009, 18(1), 73-8.

Alfven wave propagation is considered along the magnetic field lines in inhomogeneous and resistive plasma. In the presence of dissipative factor perturbation of the physical quantity is responsible for phase-mixing of the linear plane AlrVen wave. Sink of Alfven wave energy leads to the strong transverse gradients in the wave amplitude. Decay of the phase-mixed Alfven wave energy is cause of generation of acoustic wave, which propagates along magnetic field direction. Fast and slow magnetosonic waves emerged from the non-linear solution of considered MHD model. The fast magnetosonic waves, originated from the coronal base, can propagate upwards into the corona and dissipates its mechanical energy as heat. It is conversion of phase-mixed Alfven wave energy into thermal energy via magnetosonic waves. The fast magnetosonic waves prove to be a likely candidate to heat the solar corona. We studied phase mixing of a three dimensional MHD wave in the compressive, three dimensional regime. Coupling of its compressive part does not alter the behavior of the Alfvenic part of a compressible MHD wave. The dependence upon resistivity of the Alfvenic pan of the MHD wave and decay of its amplitude is shown using 3d numerical code simulation.

5 illus, 27 ref

012500   Prasad L;Joshi V K (Physics Dep, MB Govt. PG College, Haldwani, Nainital-263 141, Email: lprasad@iucaa.enet.in) : Power law and hydrodynamical approach of nanoflare heating. Asian J Phys 2009, 18(1), 79-88.

The concept of coronal heating by nanoflare is shown to be the characteristic of active regions which results presumably from a large number of more or less random heating agents. The flare associated with small impulsive events of magnetic energy dissipation from 5 x 10^{23 to 1026 ergs are called nanoflares and are treated as heating agents. The analysis of these agents is represented by a power law distribution as a function of their energies with a negative slope of 1.5 and more. We discussed the physical characteristics and features of nanoflare heating process in respect of power law distribution and formulated the coronal luminosity. We estimated the radiation energy and generation rate of nanoflares and discussed the hydrodynamical simulation results of nanoflare with the variation of power law index α.}

3 illus, 1 table, 36 ref

012499   Pradeep Mohan;Harish Kumar (NO, National Physical Laboratory, New Delhi-110 012, Email: pardeep@mail.nplindia.ernet.in) : Static expansion primary vacuum standrad - Part 1: determination of the volume ratio of the expansion stage. MAPAN 2009, 24(2), 101-9.

Measurement of volume ratio forms an essential part of the characterization of a static expansion system (SES) for the generation of pressures in the medium and high vacuum region. Because of the complexity of the vacuum chambers, it is not possible to determine the absolute volumes of the chambers involved. Hence an expansion process is resorted to, in which the gas enclosed in the small volume at a known pressure is allowed to expand, under isothermal conditions, into the large volume. The accuracy of the volume ratio thus determined depends on the stability of the vacuum gauges used for the measurement of initial and the final pressures and the ambient temperature. High accuracy resonant silicon gauges (RSGs) of two different ranges, one 130 kPa full scale and the other 1 kPa full scale for measurement of the initial and final pressures are found to be useful. Reports the results obtained with these RSGs for the measurement of the volume ratio of the National Physical Laboratory, India (NPLI) SES which is nominally 2820. With the use of the RSGs, and calibrated platinum resistance thermometers (PRTs) mounted inside the vacuum chambers, it has been possible to measure the volume ratio within the relative expanded uncertainty (k = 2) of 0.0014. The results of the volume ratio determination exercise are given.

4 illus, 1 table, 9 ref

012498   Peksa L;Prazak D;Gronych T;Repa P;Vicar M; Tesar J;Krajicek Z;Stanek F (Faculty of Mathematics and Physics, Charles University in Prague, V Holesovickach, 180 00 Praha 8, Czech Republic, Email: ladislav.peksa@mff.cuni.cz) : Primary vacuum standard for UHV range - standing experience and present problems. MAPAN 2009, 24(2), 77-88.

Accurate calibrations of gauges to ever lower pressures (higher vacuum) are increasingly becoming necessary. The calibrations over the entire ultra high vacuum (UHV) range i.e. up to 10-10 Pa are already sometimes demanded by the users of vacuum measuring devices. Standards covering part of this range are available in some national metrological laboratories while primary standards covering the entire UHV range are under development. However, the most suitable principle of the primary standard for generating such a low pressure is still not clear. In spite of some attempts during the last century no sufficiently accurate absolute ("calibration-free") gauge for high vacuum (HV) and UHV ranges has been developed to date. Apparatuses for generating gas pressure in a dynamic flow control method will continue to be used as primary standards for the UHV range, but, by virtue of technical difficulties, the equilibrium (Maxwellian velocity distribution) will be severely disturbed during the process of pressure generation that the pressure in the chamber will not be defined as a simple scalar quantity. This principal problem must be solved first by the development of a primary UHV standard. Another serious problem in the design of an apparatus for generating controlled pressures on the order of 10-10 Pa requires the uncontrolled changes of gas pressure to 10-12 Pa or lower. Hence an extremely high vacuum (XHV) apparatus must be used in which the requirements concerning the pumps and the outgassing rate from the materials are kept very strict.

^iia7 illus, 1 table, 49 ref

012497   Pawar P P;Chaudhari V A;Bichile G K (Physics Dep, Dr.B.A.M. Univ, Aurangabad-431 004) : Synthesis and characterization of nano thin films. Bionano Front 2010, NCANDT(spl), 166-71.

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. 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

012496   Patil S;Kathare R V;Nimbore S R;Algude S G; Kadam R H;Mane D R (Material Science Research Lab, Shrikrishna Mahavidyalaya Gunjoti, Osmanabad, Maharashtra) : Magnetic loss studies in Mn substituted Li_0.5Fe_2.5O₄. Bionano Front 2010, NCANDT(spl), 155-9.

Li-Mn ferrite samples, with compositional formula Li_0.5Fe_2.5-xMn_xO₄, 'x' ranging from 0.0 to 1.0 in steps of 0.2 were synthesized by sol-gel auto combustion technique and have been investigated by means of X-ray diffraction and magnetization. Investigations on the series of manganese-substituted lithium ferrites reveal the destructive effect of manganese ions on the ordering of Li cations in the spinel-type crystal lattice. Lattice constant increases from 8.322 A (x = 0.0) to 8.363 A (x = 1.0). M-H loops have been traced for all the samples and the various hysteresis parameters like magneton number, coercivity, remanant magnetization and remanence ratio have been studied as a function of composition. Saturation magnetization decreases from 49.53 (emu/gm) to 5.74 (emu/gm), whereas coercivity varies from 140 -130 Oe with Mn substitution.

6 illus, 22 ref

012495   Patil P;Shitre A R;Kadam R H;Mane D R;Rathod S D (Materials Science Research Lab., Shrikrishna College, Gunjoti, Osmanabad, Maharashtra) : XRD investigation of Mg_1-xMn_xCrFeO₄ (0.5 <60> x <60> 1.0). Bionano Front 2010, NCANDT(spl), 51-5.

Solid solutions of spinel-type oxides with the composition Mg_1-xMn_xCrFeO₄ (x = 0.5< x < 1.0 1.0) were prepared with sol-gel auto combustion synthesis. The synthesized samples were annealed at 600 °C for 4 h. X-ray diffraction patterns were taken to examine spinel crystal structures. An analysis of X-ray diffraction patterns reveals the formation of single phase cubic spinel structure. The lattice constant increases with increase in Mn content. The X-ray density increases with increase in Mn content. The crystallite size calculated by Scherrer formula is in the range of 35-41 nm. Porosity decreases with Mn substitution. Hopping length increases with increase in Mn content x.

6 illus, 1 table, 20 ref

012494   Patil P;Birajdar D D;Haralkar S J;More S S; Hogade V S;Kadam R H;Rathod S D;Mane D R (NO, Shrikrishna Mahavidyalaya, Gunjoti, Osmanabad-413 613) : Site occupy of Mn substituted Mg-Cr nanocrystalline ferrite. Bionano Front 2010, NCANDT(spl), 112-16.

In the present study, Mg_1-xMn_xCrFeO₄ (0.0 ≤ x ≤ 0.4) ferrites were prepared by sol-gel method, aiming to study the relationship between cation distribution and concentration of the Mn substitution. X-ray diffraction pattern reflected that the synthesized powders were single spinel structure, with particle size of about 23-34 nm. The results indicated that with increase of Mn substitute concentration, the diffraction peaks shifted slightly towards the lower angles and the lattice parameter (a) increased. Cation distribution estimated from Bertaut method suggested that Mn, Mg and Fe ions occupy tetrahedral A site as well as octahedral B site, whereas Cr have strong preference towards octahedral B site. Ionic radii of A-site decreases where as ionic radii of B-site increases with increasing Mn content x.

4 illus, 2 tables, 16 ef

012493   Pathan A N;Kalyani S;Pangal A A G (Physics Dep, AUBHS&JC, Pune-41100, Email: amjadkhan777@gmail.com) : Synthesis & magnetic studies of Ni_0.6Zn_0.4-xCu_xFe₂O₄ nanoparticles. Bionano Front 2010, NCANDT(spl), 60-3.

Ni-Zn-Cu ferrite nanoparticlesfof the system, Ni_0.6Zn_4-xCu_xFe₂O₄, were synthesized by a soft chemical approach of co-precipitation method. These nanoparticles were separated into four batches and they were annealed at different temperatures from 600 to 1200°C for improved crystallization. All the samples were then characterized by X-ray diffraction, vibrating sample magnetometer and ferromagnetic resonance spectrometer techniques. The XRD patterns confirm spinel structures while the particle sizes ranging from 9.8 to 15.5 nm increase with the increase in heat treating temperature. The magnetization values are extremely small even at 10 kOe fields with vanished hysteresis at lower heat treating temperatures; thus leading close to the superparamagnetic nature. The resonance parameters deduced from the FMR spectra are in support of the magnetisation data.

3 illus, 1 table, 17 ref

012492   Pathan A N;Kalyani S;Pangal A A G (Physics Dep, AUBHS and JC, Pune-41100) : Synthesis and characterisation of Co_0.6Zn_0.4-xCu_xFe₂O₄ nanoparticles. Bionano Front 2010, NCANDT(spl), 46-50.

The ferrite system Co_0.6Zn_0.4-x Cu Fe₂O₄ has been chosen and its structural and magnetic characterisation under different nano ferrite preparation routs is studied. Co-Zn-Cu fcrrite Nanoparticles have been prepared using sol-gel and eoprecipitation method then heat treated at different temperatures for annealing to improve crystallinity. The samples were then characterized hy X-ray diffraction technique and ferromagnetic resonance (FMR) spectrometry and the results are compared and discussed.

3 illus, 18 ref

012491   Patange S M;Lohar K S;Vijapure Y A;Jadhav S S;Jadhav S P;Shrisath S E;Mane D R;Jadhav K M (NO, Shrikrishna College, Gunjoti, Tq. Omerga, Dist. Osmanabad, Maharashtra) : Effect of Al<. Bionano Front 2010, NCANDT(spl), 82-5.

Six samples of Cu_0.7Zn_0.3 Fe_2-xAl_xO₄ (x = 0.0 to 1.0 in step 0.2) ferrite system were prepared using wet chemical method. The X-ray diffraction patterns of all the samples were recorded at room temperature which confirms the single-phase cubic spinel structure. The structural parameters like lattice constant 'a' X-ray density 'd_x' and particle size 't' were calculated by using the XRD data. The Lattice constant decreases with increase in Al³⁺ substitution in copper zinc ferrite. Magnetization measurements of all samples using the high field hysteresis loop technique at 300K. The values of Saturation magnetization and magnetic moment both decrease with increase in Al content x. The decrease in saturation magnetization and magnetic moment is attributed to the substitution of the Al³⁺ ions. Curie temperature (T_c) from susceptibility plot is found to decrease with Al concentration x.

3 illus, 1 table, 17 ref

012490   Pardeep Mohan;Harish Kumar (NO, National Physical Laboratory, New Delhi-110 012, Email: pardeep@mail.nplindia.ernet.in) : Static expansion primary vacuum standard - Part 2: characterization of two spinning rotor gauges. MAPAN 2009, 24(2), 111-18.

Discusses the determination of the volume ratio of the Static Expansion Primary Vacuum Standard (SES). Part 2 of the paper discusses in detail the use of the SES thus characterized for generating primary pressures. This standard has been used to calibrate Spinning Rotor Gauges (SRGs) at a number of pressures in the range 0.1 Pa to 1 Pa in steps of 0.1 Pa. The Gauge Coefficient at each of these pressures, defined as equal to the ratio of the indicated pressure to the true pressure is then plotted against the true pressure. The resulting straight line plot has a negative slope and its intercept equals the gauge coefficient. Two SRGs, NPL-0 and NPL-2 thus calibrated are used (i) as a device for measuring the pressure rise in the flowmeter of the National Physical Laboratory, India (NPLI) orifice flow system and (ii) as a secondary standard for the calibration of the user gauges.

3 illus, 4 tables, 12 ref

012489   Padampalle A S;Chavan S T;Shinde S S;birajdar D S (Physics Dep, S.C.S. College, Omerga-413 606) : Electrical and dielectric properties of Ge-doped Cu-Zn ferrite. Bionano Front 2010, NCANDT(spl), 105-11.

Ge-doped Cu-Zn ferrites with compositions of Cu07_+xZn0.3Ge_xFe2_2xO4 where x = 0.0, 0.1 to 0.6 were prepared by standard ceramic method. D. C. resistivity (ρ_dc), dielectric constant (ε'), dielectric loss (ε") and loss tangent (tanε) were measured as a function of temperature from room temperature up to 800°K. D. C. electrical resistivity of all ferrites sample is found to decreases with increasing temperature, with change of slope at magnetic transition (T_c). The activation energy in ferrimagnetic region is in general less than that in paramagnetic region. On increasing temperature the dielectric constant (ε'), dielectric loss (ε") and loss tangent (tanε) are increased significantly. Seebeck coefficient (α) were measured as a function of temperature from room temperature up to 650°K. The measurement showed that the on substitution of Ge⁴⁺ tend to convert Cu-ferrite from n-type to p-type semiconductor. The results were analyzed on the basis of the small polaron model.

6 illus, 2 tables, 26 ref

012488   Murade P A;Sangawar V S;Chaudhari G N;Kapse V D;Bajpeyee A U (Physics Dep, R.D.I.K.and K.D. College, Badnera-444 701, Email: pamurade@gmail.com) : Preparation and ac electrical conductivity of nanocrystalline LaFeO₃. Bionano Front 2010, NCANDT(spl), 188-90.

Perovskite structures nanocrystalline LaFeO₃ powder was prepared using La(NO₃)₂, Fe(NO₃)₂ as a raw materials, citric acid (CA) as a chelating agent and ethylene glycol (EG) as cross linking agent. The formation of the materials has been confirmed by X-ray diffraction study. A preliminary analysis of XRD data indicates that the samples were single phase with orthorhombic structure. Electrical conductivity has been found to increase substantially at higher temperature (>300°C) and it may be attributed possibly to the oxygen vacancies. Conductivity spectrum analysis suggests the hopping of charge carrier among localized site as the possible mechanism for electrical conduction.

3 illus, 11 ref

012487   Munde S G;Kamble S M;Kathare R V (Physics Dep, KSGM, Dharmapuri, Dist. Beed, Maharashtra) : CdS thin films act as low energy pass optical filters in solar cells. Bionano Front 2010, NCANDT(spl), 12-15.

Cadmium Sulphide (CdS) thin films deposited on glass substrates by chemical bath deposition (CBD) technique. The chemical bath deposition offers temperature uniformity throughout the solution and the control over CdS film thickness. The CdS films are grown on glass substrates by changing four parameters, viz., temperature, pH of the solution bath, dipping time of substrates and molar ratio concentration of Cadmium Chloride (CdClv>2) and Thiourea (CH₄N₂S) solutions. Further, the CdS deposited films are characterized for optical transmission and absorption measurements by means of UV-VIS spectrophotometer in the range of 200 nm to 1000 nm. The obtained optical transmission / absoiption spectra of CdS films is the nature of low energy pass optical filters used in solar cells having energy band gap 2.38 eV.

3 illus, 10 ref

012486   Motlak H J;Imam S A;Naseem Ahmad S (Faculty of Engineering & Technology, Electronics & Comm Engineering De, Jamia Millia Islamia, New Delhi-110 025, Email: hssn_jasim@yahoo.com) : Novel design of CMOS DO-CCII for use in current-mode applications. Icfai Univ J Sci Technol 2009, 5(1), 16-26.

A novel Dual-Output second generation Current Conveyor (DO-CCII) circuit using resistive compensation technique is proposed. The resistive compensation technique is a very simple and powerful technique used to improve the bandwidth of CMOS DO-CCII without extra power consumption. P - spice simulations for MIETEC 0.5 μ CMOS technology show that the current mode and voltage mode bandwidths are 2.3 GHz and 3.3 GHz respectively, with power consumption of 2 mW. The simulation results, which confirm the desired results, have been included.

7 illus, 3 tables, 15 ref

012485   Mote V D;Huse V R;Jadhav K M;Dole B N;Shah S S (Physics Dep, Dr. Babasaheb Ambedkar Marathwada Univ, Aurangabad-431 004) : Synthesis and structural properties of Mn doped ZnO nanoparticles by ceramic route. Bionano Front 2010, NCANDT(spl), 145-50.

The structural properties of the manganese doped ZnO were synthesized with nominal compositions Zn_1-xMn_xO (x = 0.00, 0.15 and 0.25) by ceramic route using ZnO and MnO₂ starting powders are studied. The samples were finally sintered at 450°C for 8h in furnace followed by furnace cooling up to room temperature. Although X-ray diffraction (XRD) patterns show a typical wurtzite structure with no additional peaks for all samples. The lattice parameters 'a' and 'c' of Zn _1-xMn_xO were calculated for the Mn doped ZnO. From the XRD pattern were found to be slightly larger than those of the undoped ZnO, which indicates substitution of Mn in ZnO lattice. The volume of unit cell, grain size and X-ray density were evaluated using XRD data and found that the volume of unit cell, grain size increases and X-ray density decreases as doping percentage increases. The functional groups and chemical interactions of Mn substituted zinc oxide samples were determined at peaks using FTIR data and to confirm the formation of crystalline ZnO nanoparticles and identified absorbed species onto the crystal surface.

6 illus, 2 tables, 29 ref

012484   More R M;Chaudhari N D;Vasambekar P N (Physics Dep, DBJ College, Chiplun, Dist. Ratnagiri, Maharashtra) : Effect of Gd<. Bionano Front 2010, NCANDT(spl), 131-5.

Gd³⁺ substituted Ni-Cd ferrite system having general formula Cd_xNi_1-xFe_2-YGd_YO₄ (x = 0.00,0.20,0.40,0.60 and 0.80, y = 0.00,0.05,0.10) were synthesized by oxalate co-precipitation method using sulphates. Initial permeability and loss factor were studied as a function of composition, temperature (at 1 kHz) and frequency in the range of 100 Hz to 1MHz.

14 illus, 13 ref

012483   Moore C P;Blaikie R J (Electrical and Computer Engineering Dep, MacDiarmid Institute for Advanced Materials and Nanotechnology, Canter, New Zealand, Email: c.moore@elec.canterbury.ac.nz) : Plasmonic superlenses: theory, practice and recent developments. Asian J Phys 2009, 18(1), 7-16.

The phenomenon of plasmonic resonance has been identified in recent times as a means of breaking the diffraction limit that hinders high performance lithography systems in use today. Experimental results based on interleaved silver and dielectric layers have shown that resolution as low as λ/6 can be achieved and that 'superlenses' are indeed realisable. However, examples of 'perfect' lenses, predicted to have true, diffraction-free performance, have yet to be fabricated. This paper uses numerical models of silver-dielectric superlenses to explore performance around and beyond the diffraction limit, examining different superlens designs and the reasons behind their specific performance enhancements and limitations.

11 illus, 23 ref

012482   Manheimer W (NO, , US Naval Research Laboratory, Washington DC, USA, Email: wallymanheimer@yahoo.com) : Hybrid fusion and energy parks as keys to sustainable development. Asian J Phys 2009, 18(1), 95-100.

Because of the long development time for fusion power, it is rarely mentioned when renewable and sustainable energy is discussed. However another option for fusion is the fusion hybrid, namely using fusion neutrons to breed nuclear fuel. This paper briefly explores this option and cites other references where more information can be found. The author asserts that with a focused development effort, fusion hybrid based power can supply large scale energy to the world by mid century.

3 illus, 16 ref

012481   Mahindrakar R M;Chavan S T;Birajdar D S (Physics Dep, Adarsh College, Omerga-431 606) : X-ray and dielectric properties of silica-doped nickel-zinc ferrites. Bionano Front 2010, NCANDT(spl), 91-4.

Polycrystalline soft ferrites, Ni_0.7+xZn_0.3Si_xFe_2-2xO₄( x = 0.0,0.1,0.2,0.3,0.4,0.5) were prepared by standard ceramic method. X-ray analysis showes that the lattice parameter decreases with increasing Si⁴⁺ and Ni²⁺ content. The X-ray density exhibit similar behaviour. Dielectric properties such as dielectric constant (ε'), dielectric loss (ε") and loss tangent (tana) have been investigated at constant frequency and varying temperature. The dielectric constant for the ferrite is approximately inversely proportional to the square root of the resistivity.

ref

012480   Lu M;Chatwin C R;Birch P M;Young R C D;Wang W (Engineering and Design Dep, School of Science and Technology, Sussex Univ, Brighton BN1 9QT, UK, Email: C.R.Chatwin@sussex.ac.uk) : Paulse width performance of a CW pumped passively Q-switched laser taking account of the Q-switch recovery time. Asian J Phys 2009, 18(1), 131-42.

A model is presented to show the effect of the absorber's recovery time on selecting an output coupler and absorber pair to generate a shorter pulse width. The pump power pumping the laser system is kept constant as is the output energy. Results are presented which compare the model predictions with and without considering the Q-switch recovery time. Simulation results are presented by considering a CW pumped Cr: YAG passively Q-switched Nd:YAG laser.

6 illus, 1 table, 27 ref

012479   Lohar K S;Patange S M;Kulkarni D R;Shrisath S E;Jadhav S S;Suryawanshi V S;Kamble S R;Mane D R (NO, Shrikrishna Mahavidayalaya, Gunjoti, Email: kslohar@rediffmail.com) : Structural and magnetic properties of vanadium substituted nano nickel cadmium ferrites, synthesized by sol -gel method. Bionano Front 2010, NCANDT(spl), 95-9.

Ni-Cd ferrite substituted with vanadium having general formula Ni _0.3.Cd_0.3 Fe₂O₄ + x V₂O₅ where x values range from 0.0 to 1.6% in steps of 0.4 by wt.% have been prepared by sol-gel method. The thermal decomposition of dried gel was studied by thermogravimetry (TA) and differential thermal analysis (DTA). The structural and magnetic properties were investigated by X-ray diffractions, infrared spectra (IR), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The XRD analysis shows, spinel ferrite is formed with a face centered cubic structure and lattice parameters are in reported range. The IR spectra shows two absorption bands, the higher frequency band (V₁) and lower frequency (V₂) are assigned to tetrahedral and octahedral complexes respectively.

5 illus, 2 tables, 16 ref

012478   Kumar V;Kumbhaj K;Sen P;Sen P K (Electronics and Instrumentation Dep, Indian School of Mines, Dhanbad-826 004, Email: vkumar52@hotmail.com) : Fiber optic temperature senson based on surface plasmon excitation. Asian J Phys 2009, 18(1), 101-6.

Metal clad fiber optic temperature sensor, which is one of the intensity modulated intrinsic sensors, has been designed and developed in the laboratory. This type of sensor is based on surface plasmon excitation. Basic principle of surface plasmon excitation has been described briefly. Design technique and experimental results have also been discussed. The present sensor has been tested in temperature range 33 - 80°C and found to be working well. Optical fiber, being dielectric, non-metallic and non-sparking, is an intrinsically safe media and hence such temperature sensors are best suited to the hazardous industries and process control applications.

3 illus, 19 ref

012477   Kumar M;Prasad U;Jha K (Physics Dep, LN Mithila Univ, Darbhanga-846 004) : Finite element method for antenna simulation. Asian J Phys 2009, 18(1), 107-12.

In this review paper Finite Element Method (FEM) for antenna simulations has been analysed and studied. Analysis of the two most commonly used approaches in practice for the development of finite element approximation of differential equation based on boundary value problem of interest has been made. FEM is based on high frequency structure simulation which has been defined and discussed briefly. This discussion presents methodologies and algorithms.

7 ref

012476   Khairnar A G;Wagh B;Tirmali P;Mahajan A M (Electronics Dep, North Maharashtra Univ, Jalgaon-425 001) : Synthesis of cerium dioxide thin films as high-K gate oxide for ulsi technology. Bionano Front 2010, NCANDT(spl), 136-9.

Thin films of rare-earth oxides such as CeO₂ are emerging materials for applications in different fields of technology; they showed excellent electrical properties such as high dielectric constant and small equivalent oxide thickness (EOT) with low leakage current density. In the present work, Ceria coating solutions were prepared using cerium chloride hepthahydrate with citric acid in mole ratio of 1:1.0 and 1:1.5 as precursory material and ethanol. Cerium dioxide (CeO₂) thin films were deposited by the sol-gel spin coating technique on Si (100) substrate. The as deposited films were annealed at 250 to 400°C temperatures in air and it is observed that, as the temperature increases the OH content reduces, in turn improves uniformity of the film. The thickness of the film is determined using ellipsometer which is in the range of 40.19-47.18 nm. FTIR characterization of films was carried out to check the conformity of the deposited films (deposition of CeO₂ is confirmed through the existence of characteristics peak below 700nm). The films were further characterized by X-ray diffractometer (XRD) to study the structural properties of films.

2 illus, 1 table, 14 ref

012475   Kawade V B;Jadhav K M (Physics Dep, L.L.D. Mahila College, Parli-431 515) : D.C. resistivity and dielectric behaviour in MgCr_xFe_2-xO₄ ferrite. Bionano Front 2010, NCANDT(spl), 181-7.

Polycrystalline samples of ferrite MgGr_xFe_2xO₄ with x = 0.0,0.1, 03, 0.5, 0.7, 0.9 and 1.0 were prepared by standard ceramic technique and have been studied by means of X-ray-diffraction, d.c. resistivity and dielectric measurements. The lattice parameter obtained from XRD data, decreases with concentration x, up to x=0.9. The cation distribution is estimated from X-ray intensity calculations. X-ray intensity calculations indicate Cr³⁺ ion occupy only octahedral [B] sites and Mg²⁺ and Fe²⁺ ions occupy octahedral (A) sites. The d.c. resistivity 'ρ' of all the samples was measured as a function of chromium content x and temperature, using two probe method. The activation energy of all the samples was found to be lower in ferrimagnetic region than that in paramagnetic region. Curie temperature obtained from resistivity data decreases. The dielectric constant measured at fixed frequency 1 KHz show strong temperature dependence.

4 illus, 5 tables, 18 ref

012474   Kapse V D;Ghosh S A;Bajpeyee A U;Kapse S D; Murade P A (Physics Dep, Arts Science and Commerce College, Chikhaldara, Maharashtra) : Structural and gas sensing properties of nanocrystalline spinel NiFe₂O₄ prepared by citrate sol-gel method. Bionano Front 2010, NCANDT(spl), 191-4.

Mixed metallic oxides especially spinels having the general formula AB₂O₄ are very important materials for technological applications. Spinel-type oxide semiconductors (ferrites) are an alternative for inexpensive and robust detection systems because of good chemical and thermal stability under operating conditions. Nanocrystalline powder of NiFe₂O₄ mixed ferrite, semiconducting oxide material, with cubic spinel structure was synthesized by the ethylene glycol mediated citrate sol-gel method. The X-ray diffraction analysis studies confirm the formation of single-phase spinel cubic structure at 700 °C. The lattice parameters of the prepared material were calculated from the XRD peaks using least square refinement and average crystallite size by Debye-scherrer formula. Further studies by Fourier transform infrared spectroscopy (FT-IR) were also conducted. The response of as-prepared NiFe₂O₄ nanoparticles to different gases (ethanol, hydrogen, hydrogen sulfide, ammonia and liquefied petroleum gas) was investigated. The results demonstrate that as prepared NiFe₂O₄ is n-type semiconducting material and it exhibited better response and good selectivity to C₂H₅OH at 300 PC. The results on response and recovery time were also discussed.

2 illus, 8 ref

012473   Kadam R H;Kadam A B;Mane D R;Shinde S S; Jadhav K M (Materials Science Research Lab, Shrikrishna College, Gunjoti, Dist. Osmanabad, Maharashtra) : Gamma ray mass attenuation coefficient and atomic number measurement in zinc ferrite. Bionano Front 2010, NCANDT(spl), 16-19.

Pure zinc fertile sample was prepared by standard ceramic technique and characterized by X-ray diffraction method. XRD pattern revealed that sample possess single-phase cubic spinel structure. The pellets of pure zinc ferrite were used as absorber. By varying the thickness of the absorber the linear attenuation coefficient (μ), mass attenuation coefficient (μ/ρ). Total atomic cross-section (σ_tot). total electronic cross-section (σ_ele) and the effective atomic number (Z_eff) were calculated. The values of gamma ray mass attenuation coefficient were obtained using a Nal energy selective scintillation counter with radioactive gamma ray sources having energy ranges form 0.360 MeV to 1.33 MeV. The experimentally obtained values of m/r and Z_eff agreed fairly well with those obtained theoretically.

2 illus, 2 tables, 18 ref

012472   Kadam G B;Jadhav K M (Physics Dep, Dr.Babasaheb Ambedkar Marathwada Univ, Aurangabad) : Effect of samarium on structural and electrical properties of Ni-Zn ferrite. Bionano Front 2010, NCANDT(spl), 64-71.

Polycrystalline ferrite samples having the general formula Ni_1-x Zn_xFe₂ Sm_yO₄ (where x= 0.0,0.1,0.2,0.3,0.4,0.5 and y=0.05) were prepared by conventional standard ceramic technique. The single-phase cubic spinel structures of the samples were confirmed by x-ray diffraction patterns. It seems that substituted Sm³⁺ decreases the lattice constant by small extent. Lattice constant is found to be increasing with Zn concentration x and x-ray density is found to be decreasing which is attributed to increase in lattice constant. The particle size is also calculated which is almost about 500 A. The hoping length L_A and L_B are found increasing, bond lengths are seen increasing with increase in Zn concentration x. This increase is attributed to increasing lattice constant. The cation distribution shows that non-magnetic Zn²⁺ occupies A-site. Ni²⁺ and Sm³⁺ are found to be diverting towards B-site. The substitution of Sm³⁺ increases the electrical resistivity of ferrite. The resistivity decreases with increasing temperature. The graphs between (logρ) and (1000/T) show two regions corresponding to paramagnetic and ferrimagnetic behaviour through straight lines. Curie temperature obtained by d. c. resistivity are in good compromise with those obtained by a. c. susceptibility. Activation energies are found greater in paramagnetic region than those in ferrimagnetic region. Resultant activation energy is observed decreased with increase in Zn concentration x.

10 illus, 4 tables, 26 ref

012471   Kadam G B;Jadhav K M (Physics Dep, Dr. Babasaheb Ambedkar Marathwada Univ, Aurangabad) : Structural and magnetic properties of rare earth doped Ni-Zn ferrite. Bionano Front 2010, NCANDT(spl), 39-45.

Polycrystalline ferrite samples having the general formula Ni_1-x Zn_x Fe_2-y Eu_yO₄ (where x= 0.0,0,1,0.2,0.3,0.4,0.5 and y=0.05) were prepared by conventional standard ceramic technique. The single-phase cubic spinel structures of the samples were confirmed by X-ray diffraction patterns. Lattice constant is found to be increasing with Zn concentration x and X- ray density is found to be decreasing which is attributed to lattice constant. The particle size is also calculated which is almost about 500 A°. The magnetization study reveals that the structure is collinear for x < 0.3 and there after it becomes non-collinear. The structure can be best illustrated by Neel's theory up to x = 0.3 beyond which Yafet-Kittel model is found applicable. The cation distribution shows that non-magnetic Zn²⁺ occupies A-site. Ni²⁺ and Eu³⁺ are found to be diverting towards B-site. It seems that substituted Eu³⁺ decreases the lattice constant by very small extent.

7 illus, 3 tables, 24 ref

012470   Kadam A B;Shinde S S;Kadam R H;Mane D R; Jadhav K M (Physics Dep, Jawahar College, Andoor, Tal. Tuljapur, Dist. Osmanabad, Maharashtra, Email: drabkadam@gmail.com) : Magnetic properties of polycrystalline mixed zinc-titanium substituted magnesium ferrites. Bionano Front 2010, NCANDT(spl), 32-4.

Mixed Zinc-Titanium substituted magnesium fertile powders of composition MgZn_xTi_xFe_2-2xO₄ (with x varying from 0 to 0.5) were prepared by standard ceramic method. The X-ray diffractographs of all the powdered compositions suggest the formation of single-phase cubic spinel ferrite showing well-defined peaks. The saturation magnetization' σ_s' and the magneton number 'n_B', are measured at room temperature using high field magnetization setup. The saturation magnetization 'σ_S' and magnetic moment 'n_B' decreases with non-magnetic Zn-Ti concentration 'x'. The X_T/X_RT Plots are observed for x ≤ 0.3. The Curie temperature obtained from X_T/X_RT plots for x ≤ 0.3 decreases with the addition of non-magnetic Zn-Ti concentration.

2 illus, 1 table, 10 ref

012469   Jagtap U S;Sharma A K (NO, Dhanaji Nana College, Faizpur-425 503, Email: jagtapuday@rediffmail.com) : OI 630 NM nightglow observations from Kolhapur (Geog. Lat., 16.8<. Asian J chem envir Res 2008, 1(2-3), 15-21.

The ground based observations of OI 630.0 nm night airglow emission have been carried out from Kolhapur (16.8° N; 74.2° E) a low latitude station in India on clear moonless nights using tilting-filter photometers, to study the characteristics of night airglow variations during the periods of geomagnetically quiet and disturbed nights in the month of April 1999. The photometer is portable and can be directed to any given direction in the sky. For the present study it was pointed to the zenith direction. The simultaneous night airglow data obtained using photometer from Kolhapur and ionospheric parameters (h'F and foF2) obtained using ionosonde at station Ahmedabad (23.02° N, 72.6° E) have been compared. It generally shows good correlation between 1/1630.0 and h'F (km) during magnetic disturbances. The time passage of reverse ionization anomaly peak at the station was found to vary between 2200 hrs to 2300 hrs at night. The association of parameter IMF B_Z with OI 630.0 nm emission also discussed. Presence of large southward IMF B₂ shows positive correlation with a large intensity increase in OI 630.0 nm emission.

2 illus, 1 table, 18 ref

012468   Jadhavar L B;Sayyad S B;Rajmane S V;Jadhav K M (NO, , M.S.P. Mandal's, Arts, Comm. and Sci. College, Kille-Dharur, Dist. Beed-431 124) : Investigation of microstructural, electrical and dielectric properties of Zn-Mn substituted nickel ferrite. Bionano Front 2010, NCANDT(spl), 72-6.

An extensive study of micro structural, electrical and dielectric properties of Zn, Mn substituted nickel ferrite has been performed, the general chemical formula of the series is NiZn_xMn_xFe_2-2xO₄ (Where x = 0.1 to 0.5). The X-ray analysis confirmed the formation of single phase of the prepared samples. By using values of the lattice Constant (a) the bond length R_A, R_B and hopping length is calculated. It is observed that the variation of RA, R_B is analogues to the variation of lattice constant (a). The IR spectra shows two absorption bands which is a common feature of a ferrite and by using these IR spectra force constant Ko, K_t is estimated. The d.c. resistivity of all the samples is studied by using two probe technique, from which curie temperature is calculated and it is observed that values of the curie temperature (T_c) goes on decreasing with increasing Zn - Mn content x. The dielectric properties for a given series are studied as a function of frequency which shows that these properties are strongly dependent upon frequency.

4 illus, 3 tables, 14 ref

012467   Jadhav S S;Patange S M;Jadhav K M (NO, , Shrikurushna Mahavidyalaya, Gunjoti, Tq. Omarga, Dist. Osmanabad, Maharashtra, Email: santosh.jadhav28@yahoo.com) : Electrical properties of nano-crystalline Co-Zn ferrites. Bionano Front 2010, NCANDT(spl), 86-90.

The nano-crystalline ferrite system Co_1-xZn_xFe₂O₄ (x= 0.0 to 0.7) is synthesized by wet chemical co-precipitation method. The electrical properties of the system have been investigated by means of DC electrical resistivity and dielectric constant measurements as a function of temperature. The plots of DC resistivity log ρ_DC versus 10³/T curve show both ferrimagnetic as well as paramagnetic regions. The Curie temperatures of the ferrite samples are calculated from these curves. The values of activation energies of the ferrite samples reveal the possibility 01 hopping mechanism as a basic phenomenon for the electrical conduction through the ferrite. The Curie temperature decreases with increasing Zn content 'x'. Dielectric constant (ε'), dielecHc loss (ε") and loss tangent (tanε) shows temperature dependence at 1KHz.

4 illus, 1 table, 14 ref