021214   Kumar D;Singh S K;Yadav S K;Mishra L K (Physics Dep, Magadh University, Bodh-Gaya-824 234) : Temperature dependence of the quasi-elastic line width of the compound Ce_1-x MxAl₂ (M=La, Y and Sc). Acta Cienc Indica-Phys 2006, 32(1), 1-8.

Studies the temperature dependence of quasi-elastic linewidth of the compound Ce_1-x M_xAl₂ where M = La, Y and Sc for x=0.3 and 0.6. The results indicates that the half width Γ 1/2 increases for both x=0.3 and x=0.6. The results are in satisfactry agreement with those of the experimental data.

2 tables, 23 ref

021213   Krishnan A;Rajamannan B (Physics Dep, Annamalai University, Annamalai Nagar-608 002) : Experimental studies on binary mixture of edible oils with toluene using ultrasonic technique. Acta Cienc Indica-Phys 2006, 32(1), 51-4.

Ultrasonic velocity measurements are carried out for edible oils like coconut oil, palm oil and castor oil with Toluene, as a common component. The adiabatic compressibility, molar volume, intermolecular free length along with their excess values have been calculated and correlated with the saturated and unsaturated fatty acid content.

3 tables, 12 ref

021212   Koul S K;Kumbhat A;Basu A (Center for Applied Research in Electronics, Indian Institute of Technolgy Delhi, Hauz-Khas, New Delhi-110 016) : Micromachined conductor backed coplanar waveguide for millimeter wave circuit application. Indian J pure appl Phys 2007, 45(4), 336-44.

Conductor Backed Coplanar Waveguide (CBCPW) lines on Si micromachined substrate are in use for more than a decade, but their detailed analysis is still not available in the open literature. This paper presents design data and closed form expressions on characteristic parameters of CBCPW lines on Si-micromachined structures that are valid up to 40 GHz. Effect of various physical parameters are studied. Procedure for deriving lumped equivalent circuit models for discontinuities on Si-Micromachined substrate as a function of discontinuity physical parameters is also presented. Scattering parameters obtained from equivalent circuit models agree well with those obtained from full wave FEM for all the discontinuity structures. To show the usefulness of the data generated on discontinuities, design of a Ka-band band pass filter is described. The results presented are useful in designing micromachined components at microwave and millimeter wave frequencies.

14 illus, 20 ref

021211   Kotlyar V V;Shuyupova Y O (Image Processing Systems Inst of the Russian Academy of Sciences, Sama, , ) : Comparison of two methods for calculating spatial modes in photonic crystal fibers. Asian J Phys 2006, 15(3-4), 307-15.

Draws a numerical comparison between two methods for calculating spatial modes in photonic crystal fibers Film Mode matching and Finite-Ditference methods. The propagation constants calculated using the above methods are shown to differ in the third decimal place. with the spatial intensity distributions of the principal mode calculated by the different methods being coincident up to about 1%. It is also interesting that the scalar mode calculated by the Film Mode Matching method coincides (to the same accuracy) with one of the components of the vector field calculated by both methods under discussion.

5 illus, 20 ref

021210   Khanna V K;Prasad M;Dwivedi V K;Chandra Shekhar;Pankaj A C;Basu J (NO, Central Electronics Engineering Research Institute, Pilani-333 031) : Design and electro-thermal simulation of a polysilicon microheater on a suspended membrane for use in gas sensing. Indian J pure appl Phys 2007, 45(4), 332-5.

Microhotplate array comprising four 100 μm x 100 μm unit cells has been designed. It has a multi-layer structure: Si-thermal oxide-polySi-PECVD (plasma enhanced chemical vapour deposition) oxide-Sputtered Pt-Gas sensing film (SnO₂). Electro-thermal simulation of the unit cell has been carried out using ANSYS. The simulations show that for an applied bias of 4 V a mean temperature of 706°C is obtained at the centre of the heater area. The heat is assumed to flow from the hot plate to the surrounding air at an ambient temperature of 30°C by conduction. The power dissipation is less than 50 mW. The paper presents the design methodology of the hotplate.

6 illus, 1 table, 9 ref

021209   Khanna V K (MEMS and Microsensors, Central Electronics Engineering Research Institute, Pilani-333 031, Email: vkk@ceeri.ernet.in) : Advances in chemical sensors, biosensors and microsystems based on ionsensitive field-effect transistor. Indian J pure appl Phys 2007, 45(4), 345-53.

Introduced as a tool for electrophysiology three and a half decades ago, the ion-sensitive field-effect transistor (ISFET) is a generic electrochemical structure offering a family of analytical devices for applications in agriculture, food processing, medical diagnostics, pharmaceuticals, paper, pulp and chemical industries, and environmental control. Besides its use as a chemical sensor, this device has also served as the electrical transduction element for many enzyme and immunological biosensors. This paper presents the current status of this microelectronic device in terms of the theoretical understanding of its operational mechanism, the techniques used for its fabrication and the measurement circuits used in instrumentation. The state of the art of ISFET as a chemical and biosensor is examined, major problems in this area are discussed, perspectives of recent interesting developments are described and future research directions are indicated. Highlights of the work done on ISFET at our institute are presented.

7 illus, 121 ref

021208   Kelly D P;Neill F T O;Ward L E;Patten R F; Hennelly B M;Liu Y;Sheridan J T (School of Electrical, Electronic & Mechanical Engineering, Coll of Engng, Mathematical & Phys Dci Univ Coll, Dublin) : Re-interpreting speckle photography with the optical fractional fourier and the linear canonical transforms. Asian J Phys 2006, 15(3-4), 317-26.

Speckle photography is a metrology technique that allows in-plane translation and small surface tilts of an optically rough surface to be determined. The most suitable optical arrangement depends on the type of motion being examined. While an imaging system is used for the estimation of in-plane translation motion, an optical Fourier transform system can be used to measure small surface tilts. 'In this paper author examined how the Optical Fractional Fourier Transform (OFRT) and the Linear Canonical Transform (LCT) can be used to provide more insight into the design and interpretation of optical metrology systems. Use of the OFRT and LCT allows optical systems, which are neither imaging nor Fourier transforming in nature to be described.

3 illus, 30 ref

021207   Kal S;Das S (Electronics & ECE Dep, Advanced Technology Centre, Indian Institute of Technology, Kharagpur-721 302) : Development of silicon and quartz based MEMS high precision accelerometers. Indian J pure appl Phys 2007, 45(4), 299-303.

Conventional electro-mechanical inertial sensors are being replaced by MEMS versions which are miniature in size, light weight, cost effective, more reliable and sensitive, low power consuming and VLSI compatible. Although silicon is the most widely used material for MEMS, quartz has some advantage for realizing inertial sensors due to its piezoelectric property. The R&D activities undertaken in the authors' laboratory in the area of MEMS based silicon and quartz acceleration sensors have been described. While the silicon accelerometer is based on the piezoresistive technique, the quartz double ended tuning fork (DETF) accelerometer works on the stress dependence of vibration frequency.

5 illus, 9 ref

021206   Jubeen S;Singh M K;Mishra L K (Physics Dep, Magadh University, Bodh-Gaya-824 234) : Evaluation of normal electron-electeron scattering (A<. Acta Cienc Indica-Phys 2006, 32(1), 13-20.

Normal electron-electron scattering (A^N _ee)_z and (A^N _ee)_skin for Cu and Al metals have been determined as a function of temperature T. The theoretical results are in good agreement with that of the experimental observation.

3 tables, 20 ref

021205   Jubeen S;Singh M K;Kumar D;Mishra L K (Physics Dep, Magadh University, Bodh-Gaya-824 234) : Effect of magnetic field on electron-electron scattering and evaluation of magnetic field dependence of the ratio A_ee(H) for Cu metal. Acta Cienc Indica-Phys 2006, 32(1), 37-42.

Effect of magnetic field on electron-electron scattering have been studied. The magnetic field dependence of the ratio A_ee(H) for Cu metal has been calculated for two magnetic field dependence function λ ⁽¹⁾_H and λ ⁽²⁾_H. The theoretical results are in good agreement with experimental observations.

1 table, 19 ref

021204   Joshi M;Kale N;Mukherji S;Lal R;Ramgopal Rao V (Micro-fabrication Laboratory, Indian Institute of Technology Bombay, Mumbai-400 076, Email: rrao@ee.iitb.ac.in) : Affinity cantilever sensor for cardiac diagnostics. Indian J pure appl Phys 2007, 45(4), 287-93.

Cardiac problems are on the rise in the Indian sub-continent due to the changing life styles and food habits. Acute Myocardial Infraction (AMI) is becoming a major concern. In this paper, we report the development of affinity cantilever based sensors for the detection of AMI with optical and electrical readouts. We designed, simulated and fabricated these cantilevers with various micro fabricated materials such as silicon dioxide, silicon nitride and SU-8. Thin films such as silicon nitride and p-type polysilicon are deposited using hot wire CVD technique. For electrical detection, p-type polysilicon was used as a piezoresistive layer. The mechanical and electrical performance parameters of these cantilevers were investigated using Atomic Force Microscope (AFM) set-up. The top surface of these cantilevers was selectively immobilized with the antibodies. Following this, antibody specific antigens were allowed to react with the cantilever surface ' in the liquid cell of AFM set-up for the optical detection. For electrical signal detection, microcontroller based signal conditioning and digital readout circuit was developed.

10 illus, 16 ref

021203   Jianbin L (State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China, Email: luojb@tsinghua.edu.cn) : Variation of surface layer during chemical mechanical polish. Indian J pure appl Phys 2007, 45(4), 403-5.

Nanoparticles have been widely used in oils and polish slurry such as chemical mechanical polish (CMP) process. The -movement of nanoparticles in liquid and the interaction between nano-particles and solid surface are very important to obtain an atomic smooth surface in CMP process. This paper presents both experimental and theoretical studies on the movement of nanoparticles in fluid and the collision between nanoparticles as well as that between the particles and solid surfaces in two phases flowing process.

6 illus, 6 ref

021202   Jaiswal A K (NO, Instrument Research and Development Establishment, Dehra Dun-248 008, Email: akj_1945@rediffmail.com) : Acquisition range prediction for thermal imagers using an intrinsic parameter characterised by ambient temperature and RH. J Optics 2006, 35(2), 74-7.

In most practical applications, it is required to predict the acquisition range performanc of a Thermal Imager (TI) in terms of user defined and measurable parameters viz. ambient temperature T_a, relative humidity RH and visibility V. Range performance of TI system has been presented as function of absolute humidity(AH) termed α (T) which is responsible for attenuation of IR radiation due to water vapour molecules present in the path length. Presentation of acquisition range as function of α (T) leads to a single range performance table/graph for TI system under consideration for predefined visibility V. The table is amenable to instant prediction of acquisition range for any set of combination of T_a and RH. The approach outlined is extremely user friendly and its versatility has been illustrated in terms of range performance of a representative thermal imaging system.

2 illus, 1 table, 6 ref

021201   Jain V K (NO, , CSIO (Delhi Centre), CSIR Complex, Pusa Campus, New Delhi-110 012) : Uncooled infrared detectors based on MEMS technologies. Indian J pure appl Phys 2007, 45(4), 304-310.

Uncooled infrared (IR) detectors are gaining importance over the HgCdTe based IR photon detectors because of their room temperature operation, low power consumption and smaller in size. Silicon micromachining has made it possible to make micro bolometer base IR detector. In a focal plane array (FPA), there is a two dimensional assembly of bolometers and each bolometer acts as a thermally sensitive pixel. The detector element consist of thermal sensitive material suspended above the readout electronics having an air gap of 2 micron and supported by thermally isolated hinges. The most important task is to design the structure of the sensor having the lowest possible thermal conductance. The characterization gives that thermal conductance and thermal mass are the deciding factors for the higher responsivity and detectivity. This paper presents a modified design based on thermal characterization of the membranes of micro bolometer. Based on our theoretical analysis, the required thermal conductance can be achieved even with short hinges. This can be done by reducing the thermal conductivity of the material of hinges. Our experimental investigations are in good agreement with this concept. This will also enhance the fill factor of the two dimensional IR array.

5 illus, 8 ref

021200   Jain R;Joshi V;Kayasth S L;Dave H;Deshpande M R (NO, Physical Research Laboratory, Navrangpura, Ahmedabad-380 009) : Solar X-ray spectrometer (SOXS) mission - low energy payload. J Astrophys Astr 2006, 27(2-3), 175-92.

Presents the first results from the `Low Energy Detector' payload of `Solar X-ray Spectrometer (SOXS)' mission, which was launched onboard GSAT-2 Indian spacecraft on 08 May 2003 by GSLV-D2 rocket. to study the solar flares. The SOXS Low Energy Detector (SLD) payload was designed, developed and fabricated by Physical Research Laboratory (PRL) in collaboration with Space Application Centre (SAC), Ahmedabad and ISRO Satellite Centre (ISAC), Bangalore of the Indian Space Research Organization (ISRO). The SLD payload employs the state-of-the-art solid state detectors viz., Si PIN and Cadmium-Zinc-Telluride (CZT) devices that operate at near room temperature (-20°C). The dynamic energy range of Si PIN and CZT detectors are 4-25 keV and 4-56 keV respectively. The Si PIN provides sub-keV energy resolution while CZT reveals <126> 1.7 keV energy resolution throughout the dynamic range. The high sensitivity and sub-keV energy resolution of Si PIN detector allows the measuring of the intensity, peak energy and equivalent width of the Fe-line complex at approximately 6.7 keV as a function of time in all 8 M-class flares studªied in this investigation. The peak energy (E_p) of Fe-line feature varies between 6.4 and 6.8 keV with increase in temperature from 9 to 34 MK. Found that the equivalent width (w) of Fe-line feature increases exponentially with temperature up to 20 MK but later it increases very slowly up to 28 MK and then it remains uniform around 1.55 ke V up to 34 MK. Compares the measurements of w with calculations made earlier by various investigators and propose that these measurements may improve theoretical models. Interprets the variation of both E_p and w with temperature as the changes in the ionization and recombination conditions in the plasma during the flare interval and as a consequence the contribution from different ionic emission lines also varies.

13 illus, 1 table, 24 ref

021199   Harish Bahadur et al (National Physical Laboratory, , Dr K S Krishnan Road, New Delhi-110 012) : Nano-structured ZnO films by sol-gel process. Indian J pure appl Phys 2007, 45(4), 395-9.

Thin films of ZnO grown by sol-gel spin method using two different precursors viz. zinc nitrate and zinc acetate have been characterized for their crystalline nature and associated nanostructures. In some cases, the films consist of nanostructures in the form of nanocrystals and nanoneedles of dimensions in the range 15-60 nm. A comparison between the physical characterization and the nanostructures of the films grown by two different precursor materials has been presented and the results are discussed in terms of the fundamental considerations governing the growth kinetics of the ZnO films.

10 illus, 6 ref

021198   Hao Y (National Key Lab of Micro/Nano Fabracation Technology, Institute Of Mi, Peking University, Beijing, 100 871) : Silicon-based MEMS fabrication techniques and standardization. Indian J pure appl Phys 2007, 45(4), 317-20.

Silicon-based MEMS fabrication technology, including bulk micromachining and sacrificial layers technology have been developed and studied. The 3-D fabrication and integration of silicon-based MEMS and standard process fabrication have been studied in the present paper.

5 illus, 7 ref

021197   Hamiuddin;Pachauri P (Mechanical Engineering Dep, Aligarh Muslim University, Aligarh) : Modeling and simulation of densification and microstructural characteristics of tungsten heavy alloys due to liquid phse sintering. Acta Cienc Indica-Phys 2006, 32(1), 71-88.

Present modelling and simulation is carried out to study the densification and microstructural properties of tungsten heavy alloys due to liquid phase sintering. A lot of experimental work has already been carried out but it does not allow the change in the value of parameters as per desired conditions. The simulation program facilitate to check the effect of variation in the value of a particular parameter. In this simulation program various properties are simulated to check the correlation among them. The properties are mainly the function of percentage solid content, grain size, dihedral angle and fractional gravity effects. The effect of change in the value of a particular parameter can be observed on various characteristic features. The model is based on the idea that during sintering the liquid phase forms, which is easily mobile, wets the solid particles completely, dissolves solid atoms and provides an easy diffusion path for them. The solid density increases by rearrangement, by the flattening of particle contacts, by filling of pores and grain coarsening in the final stage. The driving forces result from capillary stresses, from applied mechanical stresses, gravitational stress, and from the pressure of gas entrapped in closed pores. With the passage of sintering time the driving force decreases since the liquid pressure decreases and the grain coarsening plays an important role for the continued filling of larger pores. The variation in the value of parameters responsible for densification and microstructural changes are considered to held simultaneously. The computer program is developed keeping in view that the impact of the change in the value of one particular parameter can be observed 011 all characteristic features.

13 illus, 33 ref

021196   Goswami N;Krishan Lal;Miao J;Hartnagel H L (NO, National Physical Laboratory, New Delhi-110 012, Email: ngoswami@mail.nplindia.ernet.in) : Microfabrication and characterization of gallium arsenide membrane for force sensor applications. Indian J pure appl Phys 2007, 45(4), 382-6.

High-precision force sensors based on membranes of semi-insulating gallium arsenide with stable structures had been fabricated by micromachining. Their structural quality had been evaluated by high-resolution X-ray diffraction techniques. Free hanging membranes with thicknesses of <62> 2μm have been synthesized by utilizing photolithography, implantation and selective etching. Starting wafers were (100) n-type GaAs crystals with n = 3.5 x 10¹⁷ cm^-3. Implantation by 4 MeV N²⁺ (dose ≈ 10¹⁵ cm^-2) produced N compensated semi-insulating GaAs with a resistivity of 10⁹ Ω cm and breakdown voltage of <126> 60 V. An <126> 100 μm deep cavity below the membrane was produced by selective etching. A typical sensor was coiled shaped with five segments. The five-crystal X-ray diffractometer developed at NPL was employed in (+, -, +) configuration for structural characterization of the final device structures. A highly monochromated and well-collimated Mo Kα, X-ray beam of very narrow lateral width (<126> 10 μm) was employed as the exploring beam. Specimens were studied in symmetric as well as in highly asymmetric Bragg geometries with (400) and (511) diffracting lattice planes, respectively. Crystalline quality, tilt between adjoining sensor segments and the level of stress in the specimens were determined.

3 illus, 9 ref

021195   Ghosh S K;Sarkar S K;Chakraborty S (Electrical Engineering Dep, Jadavpur University, Kolkata-700 032) : Proposal for single mode fiber optic watt measurement scheme. J Optics 2006, 35(2), 118-24.

Using Faraday effect, measurement of true average power by a single mode fiber optic setup, has been proposed. Two equal length of single mode fiber coil placed over the bus bar ill conjunction with adjacent pressure coils which form the magnetic field ill the proposed fiber optic arrangement. One arm of fiber, coiled clockwise, has been subjected to a magnetic field where field due to pressure coil adds with field due to current coil and in the other arm coiled anticlockwise, the two field mention are in opposite directions. Theoretical study and experimental results show that the fiber can be used for electrical power measurement, in terms of optical power, in the particular arrangement.

3 illus, 1 table, 8 ref

021194   Dwivedi B N (Applied Physics Dep, Institute of Technollogy, Banaras Hindu University, Varanasi-221 005, Email: bholadwivedi@yahoo.com) : Physics of the Sun's hot atmosphere. J Astrophys Astr 2006, 27(2-3), 125-37.

Briefly overviews the physics of the Sun's hot atmosphere, using observations from recent solar spacecrafts: Yohkoh, SOHO, TRACE and RHESSI.

8 illus, 25 ref

021193   Dubey G;Holst B V D;Poedts S (NO, Centrum voor Plasma Astrofysica, K.U. Leuven, Celestijnenlaan 200 B, 3001 Leuven, Belgium, Email: govind.dubey@wis.kuleuven.ac.be) : Initiation of CMEs by magnetic flux emergence. J Astrophys Astr 2006, 27(2-3), 159-66.

Initiation of solar Coronal Mass Ejections (CMEs) is studied in the framework of numerical magnetohydrodynamics (MHD). The initial CME model includes a magnetic flux rope in spherical, axi-symmetric geometry. The initial configuration consists of a magnetic flux rope embedded in a gravitationally stratified solar atmosphere with a background dipole magnetic field. The flux rope is in equilibrium due to an image current below the photosphere. An emerging flux triggering mechanism is used to make this equilibrium system unstable. When the magnetic flux emerges within the filament below the flux rope, this results in a catastrophic behavior similar to previous models. As a result. the flux rope rises and a current sheet forms below it. It is shown that the magnetic reconnection in the current sheet below the flux rope in combination with the outward curvature forces results in a fast ejection of the flux rope as observed for solar CMEs. A parametric study of the emerging flux rate has been done.

6 illus, 22 ref

021192   Denisenko V G;Slyusar V V;Soskin M S;Freund I (NO, Institute of Phys, National Academy of Science of Ukraine, 46 Prospekt Nauki, Kiev-39, 03650, Ukraine) : Stokes interfermometry-first experimental results. Asian J Phys 2006, 15(3-4), 199-202.

First experimental results are presented for a new form of interferometry based on the use of crosspolarised sample and reference beams and a measurement of the Stokes parameters of the combined beam. This new method is used to obtain a high resolution phase map of a Gaussian laser beam containing an on-axis optical vortex. These initial experimental results are compared with the standard forked fringe interferometric method for measuring optical vortices, and with the theoretical phase map. Excellent agreement is found in all cases, thereby verifying the accuracy of the method, and paving the way for its use in the study of random speckle patterns, as well as in metro logic and other applications.

3 illus, 10 ref

021191   Das N C;Lahiri D;Bhattacharyya D;Poswal A K (Spectroscopy Div, Bhabha Atomic Research Centre, Mumbai-400 085) : Image evaluation of a DCM based XAFS beamline at Indus-2 SRS faacility. J Optics 2006, 35(2), 101-17.

Double crystal monochromator (DCM) based beamline is proposed to be set up at 2.5 GeV INDUS-2 SRS for XAFS studies in the fluorescence mode. With this beamline it will be possible to record XAFS spectra of diverse samples, such as, semiconductor with low metal doping, liquids, metal nanoparticles dispersed in matrix, thin films, etc. Discussed the detailed optical layout of the beamline. Imaging properties of the beamline have been evaluated by actual ray-tracing. During ray tracing authors have considered several options for the optical layout of the beamline in which focusing is done by a toroidal mirror or by two concave mirrors in the form of meridonial cylinders. It has been found that the system consisting of two concave mirrors and a bent crystal shows better focusing properties with a very small focal spot size at the final image position where the experimental sample is to be placed.

13 illus, 3 tables, 19 ref

021190   Das M;Tiwari T N (Physics Dep, National Institute of Tehcnology, Rourkela-769 008) : Preliminary survey of noise levels during the festival of Deepavali at Rourkela (Orissa). Acta Cienc Indica-Phys 2006, 32(1), 113-16.

Preliminary survey of noise levels in Rourkela during the festival of Deepavai, the most important religious festival of India, has been reported. The survey was conducted during the Puja festival of 2003 with the help of portable sound level meter. On the day of Kalipuja, noise levels were measured at 10 locations of Rourkela and on the day of Deepavali again readings were taken at those same places. Taken the noise levels on one ordinary day other than the festival. The survey shows that noise levels are significantly higher on the day of Deepavali due to the bursting of fire crackers.

1 illus, 2 tables, 2 ref

021189   Coupland J M;Halliwell N A;Alcock R D;Garner C P (Wolfson School of Mechanical and Manufacturing Engng, Loughborough University, Ashby Road, Lougborough, Leics LE11 3TU) : A k-space analysis of holographic particle image velocimetry. Asian J Phys 2006, 15(3-4), 211-22.

Introduces a new three-dimensional, k-space formulation of scalar wave propagation and describes its use in analygisl of Holographic Particle Image Velocimetry (HPIV). In particular, it is shown that the three-dimensional autocorrelation of scattered fields can be calculated from measurement of the power in the propagating plane wave components. In addition it is shown that this method, which refers to as Complex Correlation Analysis, is tolerant to phase aberrations introduced by windows or distortions introduce by the holographic recording process. A similar approach is used to analyse the Object Conjugate Reconstruction (OCR) technique to resolve directional ambiguity by introducing an artificial image shift to the reconstructed particle images. An example of how these methods are used together to measure the instantaneous flow fields within a motored Diesel engine is then described.

12 illus, 12 ref

021188   Chandra S;Bhatt V;Ravindra Singh;Sharma P;Pal P (Centre for Applied Research in Electronics, Indian Institute of Technology Delhi, Hauz-khas, New Delhi-110 016, Email: schandra@care.iitd.ernet.in) : MEMS prototyping using RF sputtered films. Indian J pure appl Phys 2007, 45(4), 326-31.

Deposition and characterization of dielectric, piezoelectric, semiconductor and conductor films by RF diode / RF magnetron sputtering process for applications in MEMS fabrication have been reported. Thin films of silicon dioxide, silicon nitride, amorphous silicon, zinc oxide and lanthanum doped lead zirconate titanate (PLZT) were prepared by RF sputtering process and extensively characterized for their structural, optical, and electrical properties. Thin films of conducting materials which are commonly used in MEMS fabrication (Cr, Au, Ti, and Pt) were also prepared by the same process. A few applications of these films in MEMS are demonstrated. It has been concluded that RF sputtering can be advantageously used for rapid prototyping of MEMS and demonstrating new ideas especially by researchers who do not have access to a well-established MEMS foundry.

11 illus, 13 ref

021187   Bhatt V;Chandra S;Sushil Kumar;Rauthan C M S; Dixit P N (Centre for Applied Research in Electronics, Indian Institute of Technology Delhi, New Delhi-110 016, Email: schandra@care.iitd.ernet.in) : Stress evaluation of RF sputtered silicon dioxide films for MEMS. Indian J pure appl Phys 2007, 45(4), 377-81.

Stress evaluation of RF sputtered silicon dioxide films for MEMS applications has been reported. The films were deposited in argon atmosphere in the pressure range 5-20 mtorr at 300 W RF power using a 3 inch diameter silicon dioxide target. The stress measurements were carried out using wafer curvature technique. All the deposited films show compressive stress except the film having thickness less than 5000 A. It is observed that sputtering pressure, film thickness and annealing temperature affect the stress in SiO₂ films. The dependence of deposition rate and etch rate on the deposition parameters were also investigated. To obtain the minimum stress in the film, the deposition parameters are optimized. An array of cantilever beams of sputtered silicon dioxide film was fabricated. It was observed that beams up to 500 micron length show no upward or downward bending indicating low stress in the films deposited under optimized conditions.

6 illus, 1 table, 10 ref

021186   Bhat K N et al (ECE Dep, Indian Institute of Science, Bangalore-560 012) : Wafer bonding - a powerful tool for MEMS. Indian J pure appl Phys 2007, 45(4), 311-16.

Wafer bonding techniques play a key role in the present day silicon bulk micromachining for MEMS based sensors and actuators. Various silicon wafer bonding techniques and their role on MEMS devices such as pressure sensors, accelerometers and micropump have been discussed. The results on the piezoresistive pressure sensors monolithically integrated with a MOSFET differential amplifier circuit have been presented to demonstrate the important role played by the Silicon Fusion Bonding technique for integration of sensors with electronics on a single chip.

11 illus, 8 ref

021185   Bhagat S K (NO, , AT Baigana, P.O. Ganeshpur, Purnea-854 301) : Analsysis of fourier transforms of quaqsi-crystals. Acta Cienc Indica-Phys 2006, 32(1), 97-100.

Analysis of Fourier transforms of Quasi-cyrstals has been presented. For quasilattice diffraction a more important factor would be the effect of the quasilattice itself other than regular lattice equivalent terms that give the transforms in a closed form involving structure factor; quasilattice factor and kinematic factor. In addition to these we have the additional problem in the case of electron diffraction. Also the subtle deviations between icosahedral model and twin models are usually extremely small and theoretical/semitheoretical computation of Fourier transform should be rigorously carried out before any reasonable claim could be made concerning peak-shift effects. The diffraction pattern has been already calculated from different finite segments of quasilattice having the same width the number of scatteres. The peak-positions have been numerically calculated starting from the positions where the peak would occur in the diffraction from an ideal quasilattice with the smallest interval possible (10^-6) and then locating the maxima nearest to them. Although the width is the same, the peak positions have been found to shift which cannot be explained by the slit-function. This clearly indicates that the arrangement of scatterers plays a crucial role in determining the diffraction pattern. In the 2-dimensional case, it has been pointed out that only scatterers lying in the circular region were used in the Fourier transform calculations.

8 ref

021184   Belic M;Petrovic M;Jovic D;Arsenovic D; Prvanovic S;Petrovic N (NO, Texas A & M Univ at Qatar, P O Box 5825, Doha, Qatar) : Counterpropagating beams in photorefractive crystals and optically induced photonic lattices. Asian J Phys 2006, 15(3-4), 283-93.

A comprehensive numerical study of counterpropagating incoherent beams in isotropic photorefractive crystals and optically induced photonic lattices in such crystals is carried out. A local model with saturable Kerr-like nonlinearity is adopted for the photorefractive media, with an optically generated two-dimensional photonic lattice written within the crystal. Different head-on incident beam structures are considered, such as Gaussians, dipoles, and vortices. Reviewed some of earlier work and present novel results on the dynamical behavior or counterpropagating beams in a finite hexagonal photonic lattice.

12 illus, 20 ref

021183   Bains B S (Physics Dep, Punjabi University, Patiala-147 002) : Nuclear magnetic moment from proton stripping reactions. Acta Cienc Indica-Phys 2006, 32(1), 63-4.

1 table, 19 ref

021182   Arjun Kumar (NO, , Adarsh Nagar, Ward No. 9, Madhipura, Bihar) : Quantum mechanical analysis of Bohr's complementary principle. Acta Cienc Indica-Phys 2006, 32(1), 101-4.

Quantum mechanical explanation for Bohr complementary principle has been presented. It is noted that the absence of interference in a detection process is due to decoherence arising from entanglement of interfering wave function branches with orthogonal detector states. The detector essentially has a quantum character and has degree of freedom that get entangled with the system under observation in the larger Hilbert space of the total wave function. The entangled wave function gets irreversibly collapsed to either of the two wave function branches when which slit information is read out from the detector. A comprehensive treatment of a macroscopic observation. However, would require a large multiparticle system and two essential ingredients of measurement such as amplification and irreversibility.

9 ref

021181   Arjun Kumar (NO, , Adarsh Nagar, Ward No. 9, Madhipura, Bihar) : Critical analysis of wave-particle duality. Acta Cienc Indica-Phys 2006, 32(1), 93-6.

Critical analysis of wave-particle duality has been presented. Although the complementarity principle holds in every situation in which non-commuting observables are involved, in the case of wave-particle duality, Bohr's extension of the principle to the classical concepts of waves and particles holds only in interference experiments because of the quantitative relationªship between intrinsic path distinguishability and mutual coherence in quantum mechanics. Bohr's extension cannot therefore be given the status of a general principle. However, all experiments are quite consistent with the Einstein-de Broglie-Bohm version of waveparticle duality in which the position of the particle which is present all the time is guided by the quantum potential determined by the total wave function, as well as with the causal model for the behaviour of light in terms of a quantum field theory. Posser's interpretation photons travel as particles along the lines of energy flow which are modified by boundary conditions (as in a double-slit configuration), resulting in a redistribution corresponding exactly to interference and diffraction patterns.

3 illus, 10 ref

020235   Woo S Y;Choi I M (Division of Physical Metrology, Korea Res Inst of Standards and Sci, PO Box 102, Yseong, Daejeon, 305-600, Republic of Korea, Email: sywoo@kriss.re.kr) : New calibration device for capacitance diaphragm gauge in the range 10 Pa to 13 kPa. MAPAN 2006, 21(3), 147-53.

Capacitance diaphragam gauges (CDGs) are electromechanical pressure sensors in which the displacement of a stretched thin metal diaphragm is detected by a capacitance measurement. They have gained widespread international popularity not only as high accuracy transfer standards but also as reliable replacements for many other vacuum gauges used in process industries. In order to calibrate such accurate vacuum gauges, laser or ultrasonic mercury manometers have been used. However, complexity, health concerns of mercury vapor, and cost of these manometers made it difficult to use in most calibration laboratories. In this article, we introduce a new calibration apparatus based on piston - cylinder technology. The minimum pressure that is necessary for balancing against tare weight, which generally corresponds to a pressure of several kilopascals, is overcome by adopting a variable bell-jar pressure method. To realize this method effectively, we developed a patented new weight loading device. This device can be used to measure pressures from 10 Pa to 13.3 kPa over four decades in tile absolute mode. Presented here the practical calibration results for three different range CDG s (133 Pa, 1.33 kPa, and 13.3 kPa).

6 illus, 2 tables, 6 ref

020234   Wongthep P;Changpan T (National Inst of Metrology, , 3/4-5 Moo 3, Klong 5 Klong Luang Prathumthani 12120, Thailand, Email: tawat@nimt.or.th) : Calculation of effective area at zero pressure on large diameter piston-cylinder assembly using dimensional measurement data for being used as the first primary pressure standard of NIMT. MAPAN 2006, 21(3), 171-5.

Many of national metrology institutes (NMls) have established and maintained their primary standards. Mercury manometers have been used as primary pressure standards for many NMIs. Nowadays pressure balances are also used. The pressure laboratory of National Institute of Metrology (Thailand) also intends to establish the first primary pressure standard. A gas pressure balance with 50 mm diameter of its piston-cylinder unit (PCU) is used. Diameter and roundness of the PCU were measured dimensionally. The effective area Ao (20°C, Patm) that will be used for calculation of pressure was calculated based on Dadson' s model using a Microsoft Excel program. The results for Ao and its standard uncertainty are presented.

2 illus, 4 tables, 6 ref

020233   Warrington R B;Lee H S (National Measurement Institute, , Bradfield Rond, Lindfield, NSW 2070, Sydney, Australia, Email: bruce.warrington@measurement.gov.au) : Development and implementation of the CIPM mutual recognition arrangement in the time and frequency activities of Asia Pacific Region. MAPAN 2006, 21(4), 263-70.

Mutual Recognition Arrangement (MRA) of the Comite international des Poids et Mesures (CIPM) has been established since October 1999, and is delivering a range of benefits to participating economies and organisations. The work of the APMP Technical Committee for Time and Frequency to implement the MRA in the Asia Pacific region is outlined, including a short history, the current state, and challenges for the future. A regional intercomparison of GPS receiver delays is also described; the comparison supports the key comparison of primary standards and extends this comparison to a wider network of APMP members.

10 ref

020232   Vijayalakshmi K;Lalitha V (Phys Dep, Cauvery Coll for Women, Tiruchirappalli, Tamil Nadu) : Acoustic parameter study of molecular interaction in polar and nonpolar liquid mixtures. Acta Cienc Indica-Phys 2006, 32(3), 381-7.

Ultrasonic velocity measurements have been made to determine the relative strengths of homo and hetro molecular interactions in liquid mixtures. Ultrasonic velocity of binary and ternary liquid mixtures of Lactic acid, Dioxane and Alcohols of various concentrations are measured using Mitral Ultrasonic Interferomete of fixed frequency 2MHZ at 25°C. The results are interpreted on the basis of the nature of molecular interaction between the solute and solvent molecules. Hydrogen bonding effect is detected in Alcohol - Dioxane and Lactic acid-Dioxane systems.

8 illus, 10 ref

020231   Verma K D;Kulshrestha L;Singh S P (Phys Dep, S.V. Coll, Aligarh-202 001) : Analysis of compression ratios of cesium chloride up to 300 K. Bar. Acta Cienc Indica-Phys 2006, 32(3), 257-62.

A simple theoretical model is developed to investigate the pressure dependence of the compression ratios of Lithium halides. The method is based on concept of modified Gruneisen parameter. The results obtained for all the crystals are discussed and compared with the available experimental data.lt is concluded that the present formulation is found to be in good agreement with the experimental data.

1 illus, 3 tables, 26 ref

020230   Verma K D;Kulshrestha L;Prakash D (Phys Dep, S.V. Coll, Aligarh-202 001, U.P) : Analysis of compression ratios of sodium halides up to 300 K. bar. Acta Cienc Indica-Phys 2006, 32(3), 331-9.

Simple theoretical model is developed to investigate the pressure dependence of the compression ratios of Sodium halides. The method is based on concept of modified Gruneisen parameter. The results obtained for alt the crystals are discussed all compared with the available experimental data. It is concluded that the present formulation is found to be in good agreement with the experimental data.

4 illus, 3 tables, 29ref

020229   Verma A S;Rathi S K;Sharma D;Bhardwaj S R (Phys Dep, B.S.A. Coll, Mathura-281 004) : Bulk modulus of NaCl structured Tm monochalcogenides. Acta Cienc Indica-Phys 2006, 32(3), 271-4.

An empirical relationship has been applied for bulk modulus determination of the rare earth monochalcogenides. The modified relation has been evolved in terms of inter atomic distance. Also applies the proposed relation on Ba monochalcogenides and found a better agreement with the values evaluated by earlier researchers.

1 illus, 1 table, 9 ref

020228   Vasantharani P;Kannappan A N (Phys Dep, Annamalai Uni, Annamalinagar-608 002) : Elastic propertides of vanadium-borate glasses by ultrasonic velocity measurements. Acta Cienc Indica-Phys 2006, 32(3), 293-7.

Ultrasonic velocity measurement in MnO, B2O3 and V2O5 composition glasses has been made at of 303K by making use of pulse echo overlap method and is used to evaluate mean ultrasonic velocity (Um), longitudinal (L), Young's (E), bulk (K) and shear moduli (G), Poisson's ratio (σ) and Debye temperature (θD). The structural and physical properties of the glass samples have been discussed in the light of elastic properties.

6 illus, 2 tables, 12 ref

020227   Tiwari CM;Tiwari R K;Pandey M K (Phys Dep, A.P.S. Univ, Rewa-484 003) : Study of variational characteristics of cosmic ray daily variation. Acta Cienc Indica-Phys 2006, 32(3), 351-6.

Reports the variational characteristics of daily variation of cosmic ray intensity for the period of 1989-2000, for Kiel and 1989 to 1997 for Tokyo neutron monitor station. The spectral characteristics have remained invariant, though with many other known variabilities, such as the superposed 22-years wave, the shift of the diurnal time of the maximum phase to hours (more prominent during alternatl1 solar cycles) and large decrease in the diurnal amplitude during sunspot minima. The investigation reported here has confirmed the presence of such variability in the diurnal variation during recent periods. Large changes during the 11 year period have been seen during alternate solar cycles. A well-defined peak around 0.3% can be easily seen for the diurnal amplitude at low cutoff rigidities in most of the years except 1995-1997. The histographic analysis of day-to-day changes shows leftward shift, with maximum frequency of diurnal amplitude around 0.2%, and the maximum diurnal Phase around 12 hours.

4 illus, 15 ref

020226   Tavella P (Instituto Nazionale Ricerca Metrologica (INRIM), , Torino, Italy, Email: tavella@inrim.it) : Time scales. MAPAN 2006, 21(4), 213-22.

Presents a tutorial on atomic time scales starting from all historical perspective and giving insight on the current atomic time scales, their definition, realisation, and the most demanding applications.

4 illus, 1 table, 1 ref

020225   Sinha B O P;Ajay Murari (Phys Dep, Vinoba Bhave Univ, Hazaribag, Jharkhand) : Evaluation of temperature dependence of electron-electron scattering rate τ<. Acta Cienc Indica-Phys 2006, 32(3), 357-64.

Temperature dependent electron-electron scattering rate for two dimensional Si inversion layer were evaluated using a theoretical formalism developed by M. Kaveh and N. Wiser [J. Phys. F13, 1207 (1983)]. Our theoretical result indicate that τee decreases with T for fixed electron density n as per experimental observations.

3 tables, 15 ref