002092   Datta S;Banerjee S (Physics Dep, City College, Kolkata, Email: swap9885@dataone.in) : On the determination of band gap of a semiconductor from the temperature dependence of reverse saturation current and forward bias voltage of a p-n junction. Phys Educ 2007, 24(4), 245-65.

The determination of band gap of the material of a p-n diode by the temperature dependence of reverse saturation current is critically dependent on the diode ideality factor (η). Modeling of a real diode and experimental data for a few diodes are presented and analysed to bring out the uncertainties in the band gap determination due to uncertainties in the determination of 77. The band gap, determined by the temperature variation of voltage drop across a forward biased diode driven by constant current source appears to be insensitive of the value of η.

14 illus, 9 tables, 7 ref

002091   Chunduru V (Physics Dep, Univ College for Women, Osmania Univ, Koti, Hyderabad-500 095, Email: ID-vardhani_c2001@yahoo.co.in) : Microwave spectroscopy in nanotechnology. Bull pure appl Sci-Sect D 2008, 27(1), 95-104.

Scanning Near-field Optical Microscopy opened up a new possibility for the usage of electromagnetic waves in characterising and imaging in Nano-scales and further extending it to used frequency EM waves like microwaves. The Scanning Tunnelling Microscopy (STM) can be used to extract the electrical images of the sample substrates by DC tunneling phenomenon. There is a possibility to couple dc signal and high frequency ac signal (Microwaves) in this tunneling process of obtaining images, where by finer details can be obtained. In view of this, in this present paper, the advantage of coupling ac and dc signals are discussed in obtaining the extra information and more precise electrical images of sample substrates.

7 illus, 7 ref

002090   Chaudhari H C;Shinde V J;Kulkarni J P (Microwave Research Centre, P.G. Dep of Physics, J.E.S. College, Jalna-431 203) : Electrical properties of dry and moist soils at 9.85 GHz frequency. Bull pure appl Sci-Sect D 2008, 27(1), 115-22.

The dielectric properties of material are function of its chemical constituents such as organic carbon, calcium carbonate, sodium, salinity and physical properties such as porosity, density, texture, component geometry, temperature and water holding capacity. The Infinite sample method is found suitable for the measurements of real (ε') and imaginary (ε") parts of the complex dielectric constant (ε*) of different soil textures with varied moisture content at room temperature. The X-band microwave setup operating at 9.85 GHz in the TE₁₀ mode with slotted section and a crystal detector is used tor measurements. The value of ε'and ε" first increases slowly and then increase rapidly with moisture content. From these measurements, the a.c. conductivity and relaxation time are also reported. The effect of soil texture and chemical composition is also observed. The result shows the remarkable change in electrical properties of dry and moist soils. The precise microwave dielectric measurements of soils and recognition of their dependence on physical and chemical composition are interesting and can be used in support of radar investigations of the Earth's geology.

4 illus, 1 table, 20 ref

002089   Boopathy K;Rajendran V (Physics Dep, Government College of Engineering, Salem-636 011, Email: boopathy-gcc@yahoo.com) : Dielectric properties of Ba_1-xSr_xZrO₃ (0≤x≤ 0.20) ceramics by a glycine - nitrate combustion synthesis. J Metall Mater Sci 2007, 49(4), 227-35.

Barium strontium zirconate Ba_1-x Sr_x ZrO₃ (0≤x≤0.20) ceramics were prepared by novel glycine - nitrate combustion synthesis. The as - synthesized powders were heat treated at 800°C for 6 h in order to get phase pure compounds. The crystal structure, microstructure and dielectric properties of the ceramics were investigated as a function of composition via X-ray diffraction (XRD) and scanning electron microscopy (SEM) respetively. The XRD patterns obtained on these powders showed the formation of pure cubic structure of barium strontium zirconate and all the compounds retained the cubic structure. The BET surface area of pure BZ heat treated powder is 2.35 m²g^-1 and strontium doped barium zirconate powders ranges from 2.6 to 3.8 m²g^-1. It has been observed that the dielectric constant and dielectric loss decreases with increase in strontium content (100 KHz)

5 illus, 2 tables, 23 ref

002088   Bhaskaranarayana A;Bhatia B S;Bandyopadhyay K;Jain P K (NO, ISRO Headquarters, Antariksh Bhavan, New BEL Road, Bangalore-560 094, Email: bhaskaranarayana@isro.gov.in) : Applications of space communication. Curr Sci 2007, 93(12), 1737-46.

Describes the evolution of satellite communications in India. Starting with the early periments like Satellite Instructional Television Experiment (SITE) and Satellite Telecommunication Experiments Project (STEP), the paper goes on to describe the unique techniques developed both for space and ground segments keeping in mind the special needs of the country especially the applications in rural areas. The conventional SatCom applications cover telecommunication, broadcasting, disaster management and several other issues. Further unique and innovative applications such as training and developmental communication, launch of Edusat for exclusively educational purposes, telemedicine, as well as village resource centres are also described.

4 illus, 5 tables,

002087   Baral K C;Nath G (Physics Dep, Salipur College, Salipur, Cuttack-754 202, Email: ganesh_nath99@yahoo.co.in) : Wiedemann-franz ratio for A thermally anisotropic, collisional magnetoplasma stream. Bull pure appl Sci-Sect D 2008, 27(1), 65-74.

The presence of beam in an electron-ion plasma embedded in magnetic field lines entails streaming or mass motion of plasma species. It causes V₀. P energy dissipation in plasma where F₀ represents streaming velocity [J.N. Mohanty, phys. Rev. A, 31. 3483 (1995); J. N. Mohanty and K.C. Baral, Phys. Plasmas, 8(12), 513, (2001)]. This leads to the significant modification of the diffusion transport coefficients. Similarly thermal anisotropy piays significant role in further modification of the above coefficients. The resultant significant modification of the WIEDEMANN FRANZ Constant (K/o) is studied both qualitative and quantitatively.

4 illus, 4 ref

001081   Vijayan M (Molecular Biophysics Unit, India Institute of Science, Bangalore-560 012) : Macromolecular crystallography in India. A historical overview. J Indian Inst Sci 2007, 87(2), 261-77.

Biological macromolecular crystallography has grown into a major activity in India encompassing nearly 20 institutions and close to twice as many research groups. It is also now at the centre stage of modern biological research in India. The problems addressed by biological crystallographers in the country span a wide spectrum and their efforts have made considerable international impact. Collective initiatives such as those involving microbial pathogens and structure-based inhibitor design have also begun to emerge.

^iia13 illus, 222 ref

001080   Upadhyay T C;Gairola S (Physics Dep, H N B Garhwal University, Srinagar (Garhwal), Uttarakhand-246 174, Email: trilokphys@yahoo.co.in) : Microwave absorption in PbHPO₄ crystal. Indian J pure appl Phys 2008, 46(10), 727-30.

Considering two-sublattice pseudospin lattice coupled mode model along with third- and -fourth order phonon anharmonic interaction terms and using double-time thermal Green's function method for PbHPO₄ crystal, expressions for shift, width, renormalized soft mode frequency, Curie temperature, dielectric constant and microwave absorption have been derived. By fitting model values in expressions, numerical values of soft mode frequency dielectric constant and loss tangent (microwave absorption) have been calculated. Theoretical results compare well with experimental results of Ohno and Lockwood [Ferroelectrics, 72 (1977)303] and Negran et al. [Ferroelectrics, 6 (1974) 179].

001079   Tripathi C C;Jain S;Joshi P;Sood S C;Dinesh Kumar (NO, Ambala College of Engineering. & Applied Research, Devasthli, Ambala, Email: jain.shruti15@gmail.com) : Development of low cost set up for anodic bonding and its characterization. Indian J pure appl Phys 2008, 46(10), 738-43.

A low cost experimental set- up for anodic bonding has been developed indigenously in the college laboratory and glass silicon bonding parameters characterized. Anodic bonding between silicon and glass substrates has been characterized in detail. The effects of magnitude of the applied voltage on the time required for complete bonding have also been investigated. The effect of voltage, point contact, bond strength and electrostatic force in anodic wafer bonding process has also been analyzed. The glass to silicon bonding at 1150V, 450°C has been successfully performed. This enables simple, but highly accurate, alignment of pre-patterned glass and silicon wafers. Fabricated devices have wide benefits like glass transparency at optical wavelengths.

001078   Thiyagarajan R;Palaniappan L (Physics Dep, SRM Engineering College, Chennai, Tamil Nadu, Email: lp_dde_au@yahoo.com) : Molecular interaction study of two aliphatic alcohols with cyclohexane. Indian J pure appl Phys 2008, 46(12), 852-6.

Sound velocity, density and viscosity values have been measured at 303 K in the two binary systems of cyclohexane + ethanol, 1-propanol. From these data, acoustical parameters such as adiabatic compressibility, free length, free volume and internal pressure have been estimated using the standard relations. The results are interpreted in terms of molecular interaction between the components of the mixtures. Observed excess value in all the mixture indicates that the molecular symmetry existing in the system is highly disturbed by the polar alcohol molecules and dispersive type interactions are existing in the systems.

001077   Suleman;Kulshrestha H;Verghese P S (School of Chemical Sciences, Chemistry Dep, St. John's College, Agra-282 002) : Measurements of acoustic parameters of vanadium laurate in liquid ammonia by ultrasonic interferometer. Oriental J Chem 2007, 23(1), 177-82.

The ultrasonic velocity of vanadium laurate confirms that there is a significant interaction between the solute-solvent molecules in dilute solution and the carboxylate molecules do not aggregate appreciable in dilute solutions. The value of Critical Micelle Concentration (C.M.C.) for vanadium laurate is in agreement with those obtained from other physical parameters. The effects of concentration and chain length of soap on ultrasonic velocity and the various acoustic parameters (Adiabatic compressibility, specific acoustic impedance, intermolecular free length, apparent molar compressibility, apparent volume, molar sound velocity, molar sound compressibility, Relative association and relative association solvation number) have been investigated.

2 illus, 1 table, 23 ref

001076   Soni P H;Bhavsar S R;Pandya G R;Desai C F (Physics Dep, Faculty of Science, The M S University of Baroda, Vadodara-390 002) : Optical band gap of In_0.1Bi_1.9Te₃ thin films. Indian J pure appl Phys 2008, 46(11), 806-8.

Thin films (In_0.1Bi_1.9Te₃ ) were grown using the thermal evaporation technique on a (001) face of NaCl crystal as a substrate at room temperature. The optical absorption was measured in the wave number range 500-4000 cm^-1. From the optical absorption data, the band gap has been evaluated and studied as a function of the film thickness and deposition temperature. The band gap increases with decreasing thickness, a result normally associated with quantum size effect. The deposition temperature does not seem to affect the band gap as indicated by the results. The data indicate absorption through direct interband transition with a band gap around 0.14 eV.

001075   Somashekar R (Studies in Physics Dep, Mysore Univ, Manasagangotri, Mysore-570 006, Email: rs@physics.uni-mysore.ac.in) : Line profile analysis and crystal structure of fibers. J Indian Inst Sci 2007, 87(2), 213-19.

Line profile analysis, of X-ray diffraction data collected from samples like metal oxides, polymers, polymer blends and fibers (both man-made and natural), has become a common tool to obtain information of microstructure and lattice defects. Such analysis also have significant effect on the crystal structure of samples. Review deals with various line profile analysis techniques including latest developments in the field and their application in crystal structure determination, especially in the case of fibers.

^iia4 illus, 2 tables, 35 ref

001074   Singhal D K;Usha Singh;Singh A K (Physics Dep, University of Rajasthan, Jaipur-302 004, Email: gangwarus@yahoo.com ) : Effective thermal diffusivity of perishable produce as a function of temperature by transient method. Indian J pure appl Phys 2008, 46(12), 862-5.

Effective thermal diffusivity of vegetables/fruits has been determined in the temperature range 0 - 45°C. The thermal diffusivity is measured by a transient technique using temperature probes (thermocouples) inserted in the sample at a distance of 2 mm. One dimensional transient temperature distributions T(r, t) generated in the sample are measured at different positions at discrete times. An ADAM data acquisition module is used to simultaneously read and store the temperature after every one second interval with a precision of 0.001°C by GeniDaq software. The cubic spline interpolation technique is used to calculate effective thermal diffusivity. The temperature dependent thermal diffusivity has been determined for Cucumis sativus (L), Luffa acutangula (L.), Lagenaria siceraria (L.), Malus domestica (L.) and Musa acuminate (L.). The effective thermal diffusivity increases continuously with temperature.

001073   Sharma P;Chauhan S;Chauhan M S;Syal V K (Chemistry Dep, Himachal Pradesh University, Shimla-171 005, Email: drpoonamsharma@rediffmail.com) : Ultrasonic velocity and viscosity studies of tramacip and parvodex in binary mixtures of alcohol + water. Indian J pure appl Phys 2008, 46(12), 839-43.

The viscosity and ultrasound velocity of narcotic analgesic drugs in aqueous mixtures of methanol, ethanol and 1- propanol have been studied.. Various acoustical parameters have been obtained which include viscous relaxation time (Γ), free volume (V_f), internal pressure (pi) and molar cohesive energy (MCE). The dependence of these properties on solvent composition is found to originate from hydrophobic hydration phenomenon.

001072   Shaikh A M (Solid State Physics Div, Bhabha Atomic Research Centre, Mumbai-400 085, Email: shaikham@barc.gov.in) : Investigations in high temperature single crystal X-ray crystallography. J Indian Inst Sci 2007, 87(2), 237-59.

Investigations in the field of high temperature single crystal X-ray diffraction were done at Physics Department, Indian Institute of Science, Bangalore during 1970-1980. Varieties of heater attachments based on resistance heating, gas flame and hot air flow technique were developed for use with commercially available single crystal X-ray cameras and diffractometers. These include heater attachments for Weissenberg camera (1000°C-3000°C), Hilger & Watts linear diffractometer (1000°C), Charles Super Co. precession camera (1000°C), a complete high temperature Weissenberg camera for single crystal data collection up to 400°C in vacuum or inert gas atmosphere and up to 900°C in air, a high temperature attachment for Enraf-Nonius CAD-4 Kappa axis diffractometer (500°C). Accurate single crystal X-ray diffraction data on NaCl, and KG were collected on linear diffractometer from room temperature to melting point for study of thermal vibration of atoms. High temperature data with CAD-4 diffractometer was collected for study of phase transition in ferroelectric sodium metavanadate and dicalcium lead propionate, semiconductor to metal transition in Ti₂O₃ and Jahn Teller induced phase transition in CsCuCl₃. The present article describes the salient features of the various high temperature techniques developed and high temperature crystallographic studies made.

^iia31 illus, 4 tables, 42 ref

001071   Shah N A;Quadri M;Iqbal S Z (Electronics & Instrumentation Technology Dep, University of Kashmir, Srinagar-190 006, Email: ku_munazah@yahoo.co.in) : High output impedance current-mode allpass inverse filter using CDTA. Indian J pure appl Phys 2008, 46(12), 893-6.

A novel current-mode (CM) first-order all-pass (AP) inverse filter has been presented. The proposed circuit has two inputs and a single output with both the inputs providing the first-order all-pass inverse responses independently. The circuit employs bare minimum number of both active and passive components, viz. one each of CDTA, capacitor and resistor. The output current is available at high impedance thereby making the circuit very attractive from the viewpoint of cascadibility. The realizibility condition is simple. The theoretical results are verified by PSPICE simulation.

001070   Selvakumar M;Krishna Bhat D (Chemistry Dep, National Institute of Technology, Karnataka-575 025, Email: denthaje@gmail.com) : Molecular interactions of polymethyl methacrylate and polyethyeleneglycol solutions in tetrahydrofuran. Indian J pure appl Phys 2008, 46(10), 712-8.

The ultrasonic velocity, density and viscosities of the polymethylmethacrylate (PMMA) and polyethyleneglycol (PEG) solutions in tetrahydrofuran (THF) have been measured in the temperature range 293-313K. Using these data, free energy of mixing, solvation number and different polymer-solvent interaction parameters for the solution systems have been calculated to know the presence of molecular interactions in the system. The trends in the variation of the solution property parameters indicate the existence of positive molecular interactions between the polymer and the solvent in solutions. The results also show the presence of higher degree of interaction between PEG and THF in solution compared to PMMA and THF.

001069   Sankar S;Gopchandran K G (Optoelectronics Dep, University of Kerala, Kariavattom, Thiruvananthapuram-695 581, Email: gopchandran@yahoo.com) : Effect of growth parameters on structural, electrical and optical properties of titanium oxide thin films. Indian J pure appl Phys 2008, 46(11), 791-6.

Semi-transparent and highly conducting nanostructured titanium oxide thin films have been prepared using pulsed laser deposition technique. Films deposited on quartz substrates, kept at 773 K, are shown to have resistivity of 2.9'10^-4 Wm and a maximum optical transmittance of 50%. The characterizations of the films are done with X-ray diffraction, Raman spectroscopy, Scanning electron microscopy, UV-visible spectroscopy and conductivity measurements. Eventhough annealing transformed the films from amorphous to nanocrystalline phase with preferential growth along (110) plane of the rutile TiO₂, the grain size as well as the voids between the grains after transformation, have been seen to be governed by the kinetics and thermodynamics during deposition of the films. The optical transmittances of the films have been found to increase with annealing temperature. Optical constants are derived from the transmission spectra and the refractive index dispersion has been discussed in terms of the single oscillator-Wemple and Didomenico model.

001068   Sanjay Kumar N R;Chandra Shekar N V;Sekar M; Subramanian N;Chandra Mohan P;Srinivasan M P;Parameswaran P;Sahu P C (Materials Science Div, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102) : Diamond and diamond-like carbon in laser heated diamond anvil cell at 16.5 GPa and above 2000 K from pyrolitic graphite. Indian J pure appl Phys 2008, 46(11), 783-7.

Diamond and diamond like carbon have been synthesized by direct conversion of pyrolitic carbon at pressure, 16.5 GPa and temperature, ~ 2000 K using a Laser Heated Diamond Anvil Cell (LHDAC) facility. The formation of diamond and diamond like carbon is confirmed by micro-Raman and scanning electron microscopy. The synthesised material has been found as opaque and colourless. The diamond crystals formed in this process are of micrometer size having regular facets. In this experiment, the diamond formation pressure is much lower than reported in shock pressure experiments.

001067   Saha R K;Sharma S K (NO, LBUM-CRCHUM, University of Montreal, Canada) : Determination of accuracy of particle size by acoustic scattering using a modified Born approximation. Indian J pure appl Phys 2008, 46(11), 761-70.

Accuracy of a recently proposed modified Born approximation (MBA) has been examined for size determination of an isolated scatterer. Two methods have been employed for this purpose. One is based on the analysis of the angular scattering pattern of plane waves and the other on analysis of the power spectrum of the backscattered pulse. In each case, domain of validity of the modified Born approximation for size determination has been assessed for two exactly soluble test models, namely, the scattering by a sphere and an infinitely long cylinder. For completeness, comparisons with conventional Born approximation (BA) results have also been made. The performances of the approximations have been examined for scatterers whose size parameters vary over a range 3 to 75. Mismatches of the density and compressibility are less than 15% in these calculations. Numerical results show that MBA indeed has a larger validity domain in comparison to BA for an intermediate size weak scatterer.

001066   Rudramadevi B H;Buddhudu S (Physics Dep, Sri Venkateswara University, Tirupati-517 502, Email: bh.rudramadevi@gmail.com ) : Spectral and thermal analysis of Sm<. Indian J pure appl Phys 2008, 46(12), 825-32.

Optical and thermal properties of Sm³⁺ and Dy³⁺: B₂O₃-BaO-LiF/AlF₃ glasses have been studied. These optical materials have been characterized from the measurement of their XRD, FTIR, absorption, excitation, emission spectra and DTA-TG profiles. From the recorded photoluminescence spectra of samarium (Sm³⁺) glasses, four emission transitions; ⁴G_5/2 → ⁶H_5/2 (565 nm), ⁴G_5/2 → ⁶H_7/2 (601 nm), ⁴G_5/2 → ⁶H_9/2 (648 nm) and ⁴G_5/2 → ⁶H_11/2 (710 nm) with l_exci = 401 nm (⁶H_5/2 → ⁴F_7/2) have been observed. In the case of dysprosium (Dy³⁺) glasses, three emission transitions; ⁴F_9/2 → ⁶H_15/2 (485 nm), ⁴F_9/2 → ⁶H_13/2 (578 nm) and ⁴F_9/2 → ⁶H_11/2 (667 nm) with l_exci = 448 nm (⁶H_15/2 → ^{4I_15/2) have been observed. For the prominent emissions only, the decay curves have been recorded in order to evaluate their lifetimes. The materials nature, structural trends and thermal properties have also been analyzed through the measurement of their XRD, FTIR and TG-DTA profiles.}

001065   Prakash J;Ogulu A;Zhandire E (Mathematics Dep, Faculty of Science, University of Botswana, Private Bag 0022, Gaborone, Botswana, Email: prakashj@mopipi.ub.bw) : MHD free convection and mass transfer flow of a micro-polar thermally radiating and reacting fluid with time dependent suction. Indian J pure appl Phys 2008, 46(10), 679-84.

The problem of free convection of a chemically reacting micro-polar fluid with mass transfer has been studied in the presence of a uniformly applied transverse magnetic field and variable suction. The governing, coupled, non-linear partial differential equations are solved employing a fourth order Runge-Kutta algorithm. The results show that the velocity increases as the suction parameter is increased, the chemical reaction rate decreases; while the angular velocity increases with increasing values of the suction parameter up to a point around y = 1.5, before the trend is reversed.

001064   Panwar O S;Khan M A;Bhagavanarayana G;Dixit P N;Kumar S;Rauthan C M S (Plasma Processed Materials Group, National Physical Laboratory, Dr K S Krishnan Road, New Delhi-10 012, Email: ospanwar@mail.nplindia.ernet.in) : Effect of hydrogen and nitrogen incorporation on the properties of tetrahedral amorphous carbon films grown using S bend filtered cathodic vacuum arc process. Indian J pure appl Phys 2008, 46(11), 797-805.

The electrical and mechanical properties of as- grown and also hydrogen and nitrogen incorporated tetrahedral amorphous carbon (ta-C) films, deposited using S bend filtered cathodic vacuum arc process have been reported. First, the effect of varying negative substrate bias on the dark conductivity (^SD), activation energy (ΔE₁) and residual stress of as grown ta-C films and next the effect of varying hydrogen and nitrogen partial pressure on the properties of ta-C: H and ta-C: N films deposited at a high negative substrate bias of -300V are reported. The value of ^SD is minimum at 10^-4 ohm^-1cm^-1 in as- grown ta-C films deposited at -150V substrate bias whereas the value of ΔE₁ is maximum at 0.22 eV and residual stress is maximum at 0.71 GPa in as- grown ta-C films deposited at -200 V applied substrate bias and it is found to depend on the substrate bias. Hydrogen incorporation in ta-C films decreases the value of ^{SD to 1.0x10-9 ohm-1cm-1, increases the values of ΔE₁ to 0.45 eV continuously with the increase of hydrogen partial pressure up to 1.4x10-3 mbar whereas nitrogen incorporation in ta-C films increases the value of SD to 10-1 ohm-1cm-1 and decreases the value of ΔE₁ to 0.07 eV continuously with the increase of nitrogen content up to 16.3 at. %. Low amount of hydrogen incorporation in ta-C films up to 7.4x10-5mbar hydrogen partial pressure reduces the value of residual stress and larger amount of hydrogen incorporation beyond this pressure increases the value of residual stress whereas nitrogen incorporation in ta-C films reduces the values of residual stress. The effect of hydrogen on ta-C is to give a modest gain in semi-conducting properties by passivating some defect states whereas the effect of nitrogen gives n-type doping effect in ta-C films.}

001063   Neagu E R (Physics Dep, Technical University of Iasi, B-dul D. Mangeron N. 67 Iasi-700050, Romania, Email: euneagu1@yahoo.com) : Charge-carrier injection and extraction at metal-dielectric contact under an applied electric field. Indian J pure appl Phys 2008, 46(11), 809-14.

There is charge injection/extraction at a metal-dielectric contact. In general, the problem is treated by analogy with that for metal-semiconductor contact. However, the electrical conduction through dielectrics is bulk and electrode limited. Consequently, it is difficult to discriminate between the two effects and to have specific information only about one of the mechanisms. Proposes a method that allows to determinate the sign and the value of the electric charge injected/extracted at the metal-dielectric contact. The method is based on the modification of the external electric field of a dielectric when electric charge is injected/extracted onto its surface. The lowest surface charge density measured in the presented experiments was around 1.8 10^-6 cm^-2 which corresponds to a medium distance of about 300 nm between two trapped charges. The injection/extraction process takes place no matter if there is a conduction current through the sample.

001062   Mukherjee A K (Physics Dep, Jadavpur Univ, Kolkata-700 032, Email: akm@juphys.ernet.in) : Ab-initio crystal structure determination from X-ray powder diffraction data. J Indian Inst Sci 2007, 87(2), 221-35.

Wide range of crystalline solids cannot be prepared as single crystals of suitable size and/or quality for structure analysis using conventional single-crystal X-ray diffraction techniques. In such circumstances, it is essential that structural information can be obtained from powder diffraction. Highlights some recent developments in the field of ab-initio crystal structure determination from X-ray powder diffraction data. Relevant fundamental aspects of different steps of structure determination procedure from powder data are described with particular emphasis to the challenging structure solution stage. Examples from our recent work are given to illustrate the potential of X-ray powder diffraction methodologies in determining crystal structures of several metal-organic complexes, organic compounds and pharmaceutical materials using diffraction data collected on a laboratory powder diffractometer.

^iia17 illus, 81 ref

001061   Kushwaha A K (Physics Dep, KN Government PG College, Gyanpur, Bhadohi-221 304, Email: akkphys_bu@yahoomail.com) : Zone-centre phonon frequencies for inverse spinel structure compounds. Indian J pure appl Phys 2008, 46(11), 788-90.

The zone-centre infrared and Raman phonon modes for the inverse spinel structure compounds MIn₂S₄ (M = Fe and Ni) have been calculated by using the rigid-ion model. The interatomic interaction in the octahedral bonding is stronger than the interatomic interaction in the tetrahedral bonding. It is also found that the compound NiIn₂S₄ is more ionic in comparison to FeIn₂S₄.

001060   Kishore S N;Agarwal A;Seth V P;Sheoran M S (Applied Physics Dep, Guru Jambheshwar University of Science and Technology, Hisar-125 001, Email: sanjay2000angira@yahoo.co.in) : Thermal and electrical properties of MoO₃-Bi₂O₃-B₂O₃ glasses. Indian J pure appl Phys 2008, 46(10), 719-21.

Semiconducting oxide glasses of compositions xMoO₃(40-x)Bi₂O₃60B₂O₃ have been prepared by the standard melt-quenching technique over the range 0 ≤ x ≤ 10 (x is in mol%). The various properties such as glass transition temperature, density, molar volume and dc conductivity have been measured. The values of characteristic glass transition temperature (T_g) have been found from differential scanning calorimetry (DSC) traces and corresponding specific heat capacity (C_p) was also estimated. It is found that the density of these glasses decreases as MoO₃ content is increased due to lower degree of cross-bonding between molybdenum and non-bridging oxygen ions resulting in a weakening of glass network. The dc conductivity of these samples was measured in the temperature range 523-623K. In this temperature range, the dc conductivity increases from 10^-9 to 10^-8 S/m with increasing MoO₃ content. The values of the theoretical optical basicity of these glasses have also been determined.

001059   Khatun H;Mishra A;Mahesh Kumar;Pal U N;Sharma A K;Barhai P K (Plasma Devices Technology Lab, ETA, CEERI Pilani, Rajasthan) : Study of filamentary behaviour in coaxial dielectric barrier discharge lamp. Indian J pure appl Phys 2008, 46(12), 889-92.

Filamentary discharges have been investigated at 1.5 mm dielectric-dielectric electrode gap of a coaxial dielectric barrier discharge (DBD) quartz tube filled with nitrogen gas. Different types of discharge patterns have been established in the tube using alternating field (35-45 kHz). Electrical characteristics of the discharge have been investigated, which mainly depend on gas pressure, applied frequency and voltage amplitude. The on set of the discharge current occurs earlier at higher operating voltage due to the increased value of E/n, where E is the electric field and n is the neutral gas density. The observed phenomenon occurs due to increase in rate of voltage rise time. At higher voltage, increase in net current increases the chances of electron impact. Analysis of the voltage versus charge plot (lissajous figure) supports the theory of capacitances of a double barrier discharge. The energy consumed per cycle of the DBD source measured using lissajous figure is few milli joules. Energy consumption per cycle is the key parameter for evaluating the efficiency of the device.

001058   Khanna K M;Sakwa T W;Chelimo L S;Ayodo K Y (Physics Dep, Moi University, P.O Box 1125 Eldoret, Kenya) : Solid <. Indian J pure appl Phys 2008, 46(12), 857-61.

Under very high pressure, pockets of vacuum may be created around super solid ⁴He crystals. Crystals of ⁴He may flow through pockets of vacuum, one behind the other, and since the flow in vacuum will be frictionless and ⁴He atoms being bosons can swap positions, the flow may appear to be superfluid. Thus, the crystals will not be flowing into each other, but will flow one behind the other, and since they are identical, the flow may appear as superfluidity of solid ⁴He. The thermodynamic properties of the crystal, phase transition in solid ⁴He and supersolid ⁴He, zero-point energy and the size of the region in which the particle is confined under high external pressure, have been studied.

001057   Khamis I;Ghazi N (Nuclear Engineering Dep, Atomic Energy Commission, P.O. Box 6091-Damascus, Syria) : Calculation of power density distribution in miniature neutron source detector using the MTR_PC V2.6 code package. Indian J pure appl Phys 2008, 46(11), 755-60.

Spatial power distribution for the miniature neutron source detector (MNSR) has been calculated and presented as a function of the three coordinates. Accordingly, the MNSR Safety Analysis Report will be amended with the obtained information. The spatial power distribution has shown a maximum value for power density attained in the MNSR and reaches 3.24 w/cm³, located near the core center in case where the control rod is fully withdrawn. The effect of the control rod position on such power space-distribution in all 3-axis and various location of the control rod in the core were analyzed. Total, axial and radial peak power factors have been calculated. Their values were 1.27, 1.14 and 1.116, respectively. The Argentinean MTR_PC V2.6 code package was installed and utilized for various applications, especially, neutronics calculations for nuclear research reactors. Finally, the package was verified and utilized it through the calculations of both delayed neutron fraction and the prompt neutron generation time for the MNSR. The obtained values for these two parameters were 7.8673E-03 and 8.1534E-05 s, respectively. These parameters were calculated using the core calculation code CITVAP i.e. CITATION, having the microscopic cross-section library obtained by the code BORGES based on the cell calculation WIMS code. The presented results are in a very close agreement with the published results.

001056   Katoch A C;Sharma K K (Physics Dep, Shri Atmanand Jain College, Ambala City-134 002, Email: kks@nitham.ac.in) : CKM-favored and -suppressed and meson decays to a pseudoscalar and a tensor meson. Indian J pure appl Phys 2008, 46(10), 685-90.

The two-body and meson decays emitting a pseudoscalar and a tensor meson in the final state, using the factorization hypothesis have been investigated. Employs the Isgur, Scora, Grinstein and Wise quark model to evaluate the form-factors entering the decay amplitudes. Though many decay channels are available for B^- and B^-0 meson decays, the dominant ones are: B^- → Ds^-D_{2^*0, B^-0 → Ds^-D2^*+, B^- → π^-D^*02 and B^-0 →π^-D2^*+ which have the branching ratios (%) of the order of 10^-2. To the next order dominant decays are B^- → D⁰a2^-, B^-0 → D⁰}a_2⁰/D⁰f₂, B^- → η_CK₂^*- and B^-0 → η_CK₂^-*0, B^- → K^-D₂^*0/D^-D₂^*2 and B^- → K^-D₂^*0/D^-D₂^*2 and B^-0 → K^-D₂^*+/D^-D₂^*+, which have branching ratios (%) of the order of 10^-3. Hopes that the calculated branching ratios are within the reach of current experiments.

001055   Joshi B C;Upreti D K;Dhondiyal C C;Khulbey B (Physics Dep, Kumaun University, S S J Campus, Almora (Uttarakhand), Email: dkupreti17@yahoo.co.in) : Energy transfer between optically excited Tb<. Indian J pure appl Phys 2008, 46(10), 702-5.

A study of energy transfer from optically active ions Tb³⁺ to Er³⁺ in zinc phosphate glass has been made. The evidence of non-radiative energy transfer has been noted from the decrease of Tb³⁺ emission with increasing Er³⁺ concentrations. Energy transfer mechanism is mainly found to be electric dipole-dipole in nature. Various parameters such as energy transfer probability, transfer efficiency and average donor-acceptor distances have been computed.

001054   Jafari A;Moghimi A (Physics Dep, IRIB College, Tehran (Iran)) : Selective pre-concentration and solid phase extraction of mercury(II) from natural water by alumina -loaded bis (2-hydroxylamino) glyoxime phases. Oriental J Chem 2007, 23(1), 129-36.

Alumina phase loaded with bis(2-hydroxyphenylamino) glyoxime were synthesized based on chemical binding and physical adsorption approaches. The stability of a chemically modified bis(2-hydroxyphenylamino) glyoxime especially in concentrated hydrochloric acid which was then used as a recycling and pre-concentration reagent for further uses of alumina immobilized bis(2-hydroxyphenylamino) glyoxime. The application of this alumina for sorption of a series of metal ions was performed by using different controlling factors such as the pH of metal ion solution and the equilibration shaking time by the static technique. This difference was interpreted on the basis of selectivity incorporated in these sulfur containing alumina phases. Hg(II) was found to exhibit the highest affinity towards extraction by these alumina phases. The pronounced selectivity was also confirmed from the determined distribution coefficient (Kd) of all the metal ions, showing the highest value reported for mercury(II) to occur by alumina immobilized bis(2-hydroxyphenylamino) glyoxime phase. The potential applications of alumina immobilized bis(2-hydroxyphenylamino) glyoxime phase for selective extraction of mercury(II) to occur from aqueous solution were successfully accomplished as well as pre- concentration of low concentration of Hg(II) (40 pg ml^-1) from natural tap water with a pre-concentration factor of 200 for Hg(II) off-line analysis by cold vapor atomic absorption analysis.

1 illus, 4 tables, 29 ref

001053   Ilango G;Arivazhagan M;Joseph Prince J; Balachandran V (Physics Dep, M A M College of Engineering, Tiruchirappalli-621 105) : FTIR and FT-Raman spectral investigation of 2-chloro-1,3-dibromo-5-fluorobenzene. Indian J pure appl Phys 2008, 46(10), 698-701.

Normal coordinate calculations of 2-chloro-1,3-dibromo-5-fluorobenzene have been carried out using Wilson's FG matrix mechanism on the basis of General Valence Force Field (GVFF) for both in-plane and out-of-plane vibrations. The potential energy constants obtained in this study are refined using numerical methods.

001052   Hayat S S;Choudhry M A;Ahmad S A;Akhter J I; Hussain A (Physics Dep, The Islamia University of Bahawalpur, Bahawalpur 63120, Pakistan, Email: sikandariub@yahoo.com) : Study of thermal properties of nickel using embedded-atom-method. Indian J pure appl Phys 2008, 46(11), 771-5.

Thermal properties of metals and alloys have been studied for a long due to their importance in the materials design. Molecular dynamics simulation technique is applied to investigate thermal properties of Ni. Semi-empirical potentials based on the Embedded Atom Method (EAM) have been employed to calculate lattice parameter, energy per atom, mean square displacements and radial distribution function. Thermal properties like specific heat, thermal coefficient of linear expansion and melting temperature are deduced from the calculated parameters. The results are found to compare well with the experimental results.

001051   Gunasekaran S;Natarajan R K;Kala A; Jagannathan R (PG and Research Department of Physics, Pachaiyappa's College, Chennai-600 030) : Dielectric studies of some rubber materials at microwave frequencies. Indian J pure appl Phys 2008, 46(10), 733-7.

Studies on dielectric property of natural rubber (NR) and some synthetic rubbers viz., styrene butadiene rubber (SBR), nitrile butadiene rubber (NBR), ethylene propylene diene monomer (EPDM), ethyl vinyl acetate rubber (EVA), PVC nitrile, butyl rubber, silicon rubber, neoprene, chlorosulphonated monomer, polyacrylic, fluorocarbon rubber, reclaimed rubber and polyblends of natural rubber with NBR and EPDM were carried out using microwave test bench system at X-band and K-band microwave frequencies. Analysis of dielectric property is inevitable since they determine the end electrical applications, per se, insulation. Present work is aimed at the determination of dielectric constant by using the method proposed by Robert and Von-Hippel. A systematic analytical approach was adopted in evaluating the data generated on dielectric constants for a variety of rubber materials. Interesting results were obtained by comparing dielectric constant values. The effect of microwave frequency, namely 9.6 GHz and 26GHz, as well as chemical modification brought about by vulcanization and reinforcement on dielectric constant values was probed. It appears from the study that among all samples polyblend of NR with EPDM posses interesting dielectric behaviour making it unique.

001050   Gunasekaran S;Anita B (Spectrophysics Research Lab, Pachaiyappa's College, Chennai-600 030, Email: anitabharathan@yahoo.com) : Spectral investigation and normal coordinate analysis of piperazine. Indian J pure appl Phys 2008, 46(12), 833-8.

Piperazine is a secondary amine with the molecular formula C₄N₂H₁₂. A normal coordinate analysis (NCA) has been carried out on this molecule with a systematic set of symmetry coordinates following Wilson's F-G matrix method based on D_2h point group symmetry. The frequency assignments in the FTIR and FTR spectra have been presented. A reasonable set of potential constants evaluated for this molecule has been compared with those of related molecules and are in the characteristic range. The potential energy distribution has been evaluated using the vibrational spectral data. The potential energy distribution value obtained reflects the correctness of the assignment made.

001049   Elsaid M K;Al-Naafa M A;Zugail S A (Physics Dep, College of Sciences, University of Hail, P.O.Box 2440 , Hail,Hail, Saudi Arabia, Email: mkelsaid@uoh.edu.sa) : Ground state properties of two dimensional quantum-dot helium in magnetic field. Indian J pure appl Phys 2008, 46(12), 876-9.

The ground-state properties of two-dimensional quantum-dot helium have been studied. The shifted 1/N expansion method has been used to solve the relative part Hamiltonian of two electrons confined in a quantum in the presence of an applied uniform magnetic field. The spin singlet-triplet transition in the ground state of the QD-helium is also shown. Based on comparisons, the eigen energies obtained by the shifted method are in excellent agreement with both exact and variational methods.

001048   Dhoble S J;Bramhe G V;Sonkawade R G;Moharil S V (NO, Kamla Nehru College, Sakkardara Square, Nagpur-440 009) : Phosphors MMgAl₁₀O₁₇: Eu,Dy (M=Ba,Sr,Ca) irradiated by Cs<. Indian J pure appl Phys 2008, 46(10), 695-7.

The thermoluminescence (TL) of Eu, Dy activated M MgAl₁₀O₁₇[M=Ba,Sr,Ca] phosphors has been reported. These phosphors are prepared by combustion synthesis. TL glow intensity of these phosphors is higher as compared to conventional CaSO₄:Dy TL-phosphor. M MgAl₁₀O₁₇[M=Ba,Sr,Ca] phosphors may be the possible candidate for thermoluminescence dosimetry of ionizing radiations.

001047   Chowdhury M P;Dalui S;Chakraborty B R; Mukherjee A;Pal A K (Instrumentation Science Dep, Jadavpur University, USIC Building, Calcuttta-700 032, , Email: msakp2002@yahoo.co.in) : Effect of carbon content on the mechanical properties of ternary boron-nitrogen-carbon compound. Indian J pure appl Phys 2008, 46(11), 776-82.

BNC films have been deposited on Si (100) and fused silica substrates by inductively coupled plasma chemical vapour deposition (ICP-CVD) technique using a mixture of borane-ammonia, nitrogen and methane as precursor gases. Carbon content in the films is varied by changing the concentration of methane in the precursor gases. The films are amorphous in nature. The films, thus, deposited have been characterized by using Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction and Secondary Ion Mass Spectroscopy (SIMS). Microstructural information has been obtained from SEM studies. Microhardness has been seen to decrease with the increase in carbon content and the highest microhardness observed in these films has been found to be~5.3 GPa.

001046   Chopra D;Guru Row T N (Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore-560 012, Email: ssctng@sscu.ernet.in) : In situ cryocrystallization : pathways to study intermolecular interactions. J Indian Inst Sci 2007, 87(2), 167-211.

In situ crystallization of a liquid, the subsequent determination of its molecular and crystal structure and consequent study of intermolecular interactions is an area of contemporary interest. This technique has been successfully applied for the structure determination of compounds, which are liquids at room temperature, solvents, low-melting solids, gas hydrates and ionic liquids. Particularly in solvents, the importance of how the molecules pack in the crystal lattice is of relevance in the context of polymorphic modifications and their possible implications in directing other molecules to crystallize. In situ cryocrystallization, i.e. crystallization of compounds in capillaries on the diffractometer, has offered meaningful outputs to understand both intra- and inter-molecular interactions. These offer well defined targets for molecular design, which can be exploited for the design of futuristic materials including areas like drugs, Pharmaceuticals and technologically important materials.

85 illus, 1 table, 26 ref

001045   Beri V K;Nishchal N K;Gupta A K;Rastogi V K (Photonics Div, Instruments Research & Development Establishment, Dehradun, Email: nknishchal@iitg.ernet.in) : Design parameters of hybrid correlator. Indian J pure appl Phys 2008, 46(12), 844-51.

The design issues of a hybrid correlator are discussed. The architecture of the hybrid correlator is similar to the conventional 4-f correlator, with a difference that the first Fourier transformation, filter synthesis and their multiplication are done digitally using a digital signal-processing unit. The input to the correlator is the scene/target captured either through a CCD camera or thermal imager. Wavelet-modified maximum average correlation height filter is used for catering the need of in-plane rotation, out-of-plane rotation and scale invariant target recognition. The product function is displayed over a high-speed spatial light modulator, which when illuminated with a laser light results correlation outputs due to optical Fourier transformation. A chirp function is employed with the filters that helps to capture the desired autocorrelation peak discarding the dc and one of the undesired autocorrelation peaks. The space-bandwidth of the processor and focal length of the required lens are discussed. The requirement of zero padding of the product function is also discussed. Simulation and experimental results are presented.

001044   Badr Y;Battisha I K;Salah A;Salem M A (NO, National Institute of Laser Enhancement Sciences (NILES), Cairo Unive, Egypt, Email: szbasha@yahoo.com) : Up-conversion luminescence application in Er<. Indian J pure appl Phys 2008, 46(10), 706-11.

Sol-gel derived nano-crystalline titanium dioxide films doped with 1 up to 5% Er³⁺ ions were prepared by dip coating sol-gel method. The coating sol was obtained by hydrolysis of Ti(OC₄H₉)₄ in ethanol/HCl solution. The FT-Raman and the X-ray diffraction (XRD) were carried out to determine the crystal structure of the prepared samples. The morphology SEM and the cross - sectional of the film were used to characterize the microstructure and the thickness of the prepared film. It is shown that relative homogeneous, crack-free and transparent film was achieved via dipping process at 500°C.After the excitation with laser diode at wavelength 808 nm, visible (Vis) and infrared (IR) up-conversion emissions were evidenced in the thin film samples under investigation. The up-conversion was found to depend strongly on the Er³⁺ ion concentrations. The visible emission was found to be at 540, 560, 590 and 640 nm for thin film. They are attributed to intra-4f transition of Er³⁺ ions and assigned to the (²H_11/2 + ⁴S_3/2) and ⁴F_9/2, which are populated through excited state absorption (ESA) for 808 nm excitation.

001043   Azooz M A;Abou Aiad T H M;El Batal F H;El Tabii G (Glass Research Dep, National research Center, Dokki, Cairo, Egypt) : Characterization of bioactivity in transition metal doped-borosilicate glasses by infrared reflection and dielectric studies. Indian J pure appl Phys 2008, 46(12), 880-8.

Borosilicate glasses with the addition of one of the 3d-transition metals (TiaCu) (0.1 g/100g glass) have been investigated as possible materials having bioactivity by infrared reflection spectroscopy and electrical properties after the immersion in simulated body fluid (SPF) for different interval of times. The results show obvious effects of the transition metal ions on the bioactivity of the borosilicate glasses. The results are discussed taking into consideration recent achievements that govern the formation of hydroxyapatite surface layer on glass. Also, IR and electrical results are discussed in relation to the glass composition and structure, which confirm the effect of the formation of HAp layer and the possible mixed ionic and electronic mechanisms due to the addition of transition metal oxides.

001042   Arya B S;Aynyas M;Sanyal S P (Physics Dep, Govt. Narmada College, Hoshangabad-461 001, Email: aynyas@rediffmail.com) : High pressure study of structural and elastic properties of barium chalcogenides. Indian J pure appl Phys 2008, 46(10), 722-6.

The structural and elastic properties of barium chalcogenides (BaX; X = S, Se, Te) under high pressure have been investigated by using a two body inter-ionic potential approach with modified ionic charge (Zm^e). The equation of states in NaCl type to CsCl type structural phases for BaX has been depicted and found that the volume collapses at the phase transition pressures. The phase transition pressures 7.2 GPa, 6.1 GPa, 5.0 GPa respectively for BaS, BaSe, and BaTe obtained by us, are in close agreement with experimental data (6.5 GPa, 6.0±0.2 GPa, 4.8±0.3 GPa). The bulk modulus, pressure derivatives, second order elastic constants (SOEC) and third order elastic constants (TOEC) at high pressure have been calculated, which show predominantly ionic nature of these compounds. The variation of second order elastic constants (C₁₁, C₄₄) with pressure has been presented.

001041   Acharya B S;Nayak B B (NO, Regional Research Laboratory, Bhubaneswar-75101, Email: bsacharya @ gmail.com) : Microstructural studies of nanocrystalline thin films of V₂O₅-MoO₃ using X-ray diffraction, optical absorption and laser micro Raman spectroscopy. Indian J pure appl Phys 2008, 46(12), 866-75.

Compound thin and thick films of V₂O₅-MoO₃ system deposited on plane glass and conducting glass by electron beam and vacuum deposition have been studied by X-ray diffraction, optical absorption, high temperature in-situ X-ray diffraction and laser micro Raman spectroscopy. The films were also subjected to hydrogen insertion through plasma technique. The band gaps of these films were found to lie in the range 2.26-2.84 eV and the variation in the band gaps of these compound thin films does not follow a linear relationship with the composition. This non-linear variation of the band gap has been explained on the basis of pseudo potential approach advocated by Philips and bond order length strength (BOLS) effect in nano crystalline semiconducting thin films. The interference pattern obtained in the transmission spectra has been utilized to calculate the film thickness which agrees well with that of the value obtained by weight difference method. Laser micro Raman spectra were studied for the films. Several bands observed for these thin films have been explained on the basis of different bending, stretching and lattice phonon vibration modes occurring in the films.

000131   Yadav B S;Sharma R;Ali I (Molecular Spectroscopy and Biophysics Laboratory, D.N. College, Meerut-250 002) : Vibrational spectral study of 2-chloro-6-methoxy pyridine. Oriental J Chem 2007, 23(2), 747-50.

The FTIR and Laser Raman spectra of 2-chloro-6- methoxy pyridine have been recorded in the region 4000-400 cm^-1 and 4000-100 cm ¹ respectively. The bands observed in the FTIR spectra and Laser Raman spectra are discussed by assuming the compound under C_s point group symmetry. The probable assignments of the above molecule are based on group frequency approach together with the data available for similar molecules.

3 illus, 1 table, 12 ref

000130   Singh S;Rawat B S;Tayahi M B;Hanf M;Furth S; Gessner T (Electrical Engineering Dep, University of Nevada, Reno, NV 89557, USA, Email: rawat@ee.unr.edu) : Micro mirror based Hadamard transform spectrometer. Asian J Phys 2008, 17(2), 203-12.

Hadamard transform spectrometer (HTS) is realized using micro mirror array of 48 micro mirrors. These micro mirrors are fabricated using MOEMS technology. The array is actuated by applying digital signal based on the Hadamard matrices. Thus, the wavelength associated with the micro mirror is encoded using the Hadamard matrices. The spectrum results of the known filters are determined using the spectrometer and compared with the known results. Any discrepancy in the obtained results from the known results are discussed.

10 illus, 10 ref

000129   Singh J (Applied Research Laboratory, The Pennsylvania State University, University Park, PA 16802, USA, Email: jxs46@psu.edu) : Novel nanomaterials synthesis by laser-liquid-solid interaction. Asian J Phys 2008, 17(2), 225-40.

A novel laser-liquid-solid interaction (LLSI) technique has been developed that is highly flexible and allows engineering nanomaterials in the form of particles, rods and tunes from liquid precursors. Synthesis reaction takes place in a molecular level, and the reaction rate is controlled by laser energy input, precursor solution chemistry and other processing parameters including interaction time, and thermal conductivity of solid that is spinning in the solution. By the proper selection of liquid precursor, mono-dispersed silver nanoparticles were produced with average particle size of 7-10 nm. Alloys of Ag and Ni were produced in the form of nanoparticles and nanotubes with an average diameter of 40 nm. HRTEM of nanorod exhibited that Ag acted as seed for the synthesis of immiscible of Ag-Ni alloy. Laser writing of silver exhibited 50% lower electrical resistivity, and eliminated many intermediate steps involved as compared to conventional silver patterning process.

14 illus, 4 tables, 24 ref