003121   Elahi M;Souri D (Department of physics, Faculty of Science, Razi University, Kermanshah, Iran) : Study of optical absorption and optical band gap determination of thin amorphous TeO₂-V₂O₅-MoO₃ blown films. Indian J pure appl Phys 2006, 44(6), 468-72.

The optical absorption coefficient of amorphous 40TeO₂-(60-x) V₂O₅-xMoO₃ thin films was determined in a spectral range 190-1100 nm at room temperature. The fundamental optical absorption edge was sharp. The optical gap generally increases as the proportion of MoO₃ in the mixed films increases. The width of the tail of the localized states in the band gap was determined for different compositions, which is because of the lack of long range order. The results of the usual density-of-state models of amorphous materials are presented in this paper.

7 illus, 1 table, 29 ref

003120   De S S;De B K;Adhikari S K;Sarkar S K;Bera R; Guha A;Mandal P K (Centre of Advanced Study in Radio Physics and Electronics, University of Calcutta, 91, A. P. C. Road, Kolkata-700 009, Email: de_syam_sundar@yahoo.co.in) : A report on some specific features of the atmospheric electric potential gradient in Kolkata. Indian J Phys 2006, 80(2), 167-72.

The results of measurement of surface potential gradient of the atmosphere in Kolkata (latitude: 22°34' N) will be presented. The observed fields at daytime and night time are seen to be higher and show considerable fluctuations from the daily averages of electric field and also a few hours difference in phase with the observations made at different tropical and temperate latitudes. The mean value of the potential gradient averaged for 35 days over a period from February 2004 to January 2005 is around 200 Vm^-1 and the maximum and minimum values are 1.14 times and 0.88 times the mean value, respectively. The results are discussed in terms of the variations of the local factors as well as distribution of thunderstorm activities.

10 illus, 24 ref

003119   Das G C;Karabi Devi (Division of Mathematical Sciences, Institute of Advanced Study in Science and Technology, Paschim Boragaon, Guwahati-781 035) : Propagation of soliton and its radiation in inhomogeneous discharge plasma. Indian J pure appl Phys 2006, 44(1), 31-8.

The salient features of soliton dynamics generated with the interaction of negative ions in inhomogeneous plasma has been studied through the derivation of modified Korteweg-de Vries (mK-dV) equation. Because of the complexity of plasma non-linear wave equation, the usual steady state method found to face difficulty to yield the soliton solution. The new approach known to be sine-cosine method shows the success on yielding soliton propagation along with a precursor of growing mode. The study has been furthered with higher order non-linear effect resulted on the inherent behaviour of precursor and relates the observations with actual experimental observations. The study also shows that the soliton along with the precursor, due to the interaction of negative ions, might collapse expecting a source of high-energy with radiation-like called soliton radiation. These observations could be an advanced knowledge on soliton dynamics in Townsend discharge plasma and thus might be of interest to yield soliton propagation along with precursor in laboratory and space plasmas.

4 illus, 30 ref

003118   Choudhury N;Kumar A (Department of Physics, Harcourt Butler Technological Institute, Kanpur-208 002) : Dielectric relaxation in glassy Se₇₀Te_30-xAg_x. Indian J pure appl Phys 2006, 44(1), 62-5.

Temperature dependence of dielectric constant (ε) and dielectric loss (ε) are studied in glassy Se₇₀Te_30-xAg_x where x is varied from 0 to 10 in the frequency range 1 to 10 kHz and temperature range 300-350 K. The results indicate that the dielectric dispersion exists in the above frequency and temperature range. Loss peaks in ε versus T curve could be observed in ternary Se₇₀Te_30-x Ag_x alloys. However, such loss peaks could not be observed in binary Se₇₀Te₃₀ alloy, which indicates that Ag incroporation in binary system, is responsible for such behaviour. This is explained in terms of [(D^-) (Ag⁺)] dipoles which otherwise were not present in the undoped samples.

6 illus, 26 ref

003117   Chien-Wa H;Chern-Sheng L;Sen-Yen S (Department of Electro-Optical Engineering, National United University, Miauli, Taiwan) : Improve energy distribution and beam quality of CO₂ waveguide laser array by phase-matched plate. Indian J pure appl Phys 2006, 44(6), 431-4.

According to the theorem proposed herein, if we put a phase-matched plate at the near-field of CO₂ laser array, it can restrain the far-field off-axis lobes output energy of laser beam. In addition, we use the parameter M²_x to evaluate the laser beam quality. When a phase-matched plate is used to near-field, energy can centralize to 92.92%, and the beam quality M²_x of far-field is 5.63. The phase-matched plate not only can centralize energy more efficiently but also can improve the beam quality quite substantially.

8 illus, 14 ref

003116   Chattopadhyay R;Midya S K (NO, Haripal G.D. Institute, Kharmarchandi, Hooghly-712 405, Email: rchattopadhyaya2001@yahoo.com) : Airglow emissions : fundamentals of theory and experiment. Indian J Phys 2006, 80(2), 115-66.

Discovery of airglow and ionosphere has been discussed briefly in the historical and scientific perspectives. Mentioning about all significant atmospheric parameters, different areas of research in airglow and different ionospheric layers of importance have been briefly described. Different types of airglow emissions, related chemical kinetics, different excitation mechanisms of the involved atomic, molecular or ionic species have been discussed giving stress specially to four main airglow emissions. Different layers of ionosphere, their characteristic material content and specific ranges of responses to different kinds of interacting fields etc. have also been briefly discussesd. The Sun has been described as the main source of all kinds of energetic interactions with the terrestrial ionosphere. Specific solar parameters, that are representatives of various solar activity, have been discussed briefly in relation with the corresponding covariation of various ionospheric parameters involved in the calculations of airglow intensity. Different solar activity periodicities that have been discovered upto date are mentioned Relations of different airglow emissions with ionospheric activities and specific ionospheric parameters have been briefly described The important role of ozone in the stratosphere and lower thermosphere in the production of some airglow emissions has been discussed with exemplary works. Different wellknown features of airglow intensity variations such as altitudinal variation, latitudinal variation etc have also been mentioned. Different atmospheric models have been briefly described along with their usefulness. Descriptions of different missions and campaigns with which a number of airglow experiment sets are involved, have been presented in a tabular form. Discovery of some new airglow lines, some newly proposed excitation mechanisms and related kinetics, and some remeasured or reevaluated constants and coefficients have been reported too. Effect of different types of solar activity, of different kinds of lunar influences and of various terrestrial atmospheric features, such as, geomagnetic field alignment, geomagnetic storm, lightning, earthquake, dynamical coupling between layers of thermosphere, E x B drift and ring current etc on terrestrial airglow emissions have also been briefly discussed. Some interesting airglow related features which have been discovered in recent past are discussed. Applications of different airglow features have been reported. Lastly, facts and speculation about ionospheric compositions, activities and possible airglow emission features of other inner and outer planets, satellites, comets and meteors have been discussed very briefly.

19 illus, 4 tables, 36 ref

003115   Chatterjee P;Sen B (Department of Mathematics, Siksha Bhavana, Visva Bharati, Santiniketan-731 235, Email: prasantachatterjee1@rediffmail.com) : Speed and shape of dust acoustic solitary waves in a three component dusty plasma with vortex like ion distribution. Indian J Phys 2006, 80(2), 195-9.

The existence of dust acoustic solitary waves are investigated on the non-linear, unrnagnetized homogeneous three-component dusty plasma whose components are inertial charged dust particles, Boltzmann distributed electrons and vortex like distributed ions. The Sagdeev's pseudopotential technique is employed for this study. Pseudopotential is determined in terms of U_d the dust ion speed. It is found thai there exists a critical value of u_n, the value of u_d at which u_d² = 0 and beyond which the solitary waves cease to exist.

4 illus, 37 ref

003114   Batabyal S K;Paul A;Roychoudhury P;Basu C (Department of Solid State Physics, Indian Association for the Cultivation of Science, Kolkata-700 032, Email: sspcb@iacs.res.in) : Acoustic study of nano-crystal embedded PbO-P₂O₅ glass. Bull Mater Sci 2006, 29(4), 357-63.

Nano-crystal embedded PbO-P₂O₅ glass has been prepared and characterized by XRD and TEM measurements. The ultrasonic velocity and attenuation measured within the temperature range 80-300 K show significant structure and interesting feature with the presence of nano-crystalline region. The glass samples were prepared by melt-quench method and nano-crystals of different sizes were produced by heat treatment of the glasses for different durations of heating. AU the processes were carried out at or above glass transition temperature. A theoretical model that takes account of the effects of thermally activated relaxation, anharmonicity as well as microscopic elastic inhomogeneities arising out of fluctuations has been successfully applied to interpret the variation of ultrasonic velocity and attenuation data. An interesting outcome of this application has been to propose a method for the determination of the size of nano-crystals from the ultrasonic attenuation data.

7 illus, 2 tables, 15 ref

003113   Ahmad I;Madani J H;Al-Duin B;Raffah M N (Department of Physics, Faculty of Science, King Abdulaziz University, P.O Box-80203, Jeddah, Saudi Arabia) : Extension and diffuseness parameters of semi-phenomenological nucleon density distribution. Indian J pure appl Phys 2006, 44(6), 426-30.

Extension and surface diffuseness parameters of Gambhir-Patil (GP) semi-phenomenological proton, neutron and their weighted average densities have been calculated for a large number of nuclei in the mass number range 12≤A≤238 following the method proposed by Friedrich and Voegler who used it to study the salient features of nuclear charge density distribution. It is found that the extension parameter (diffraction radius) values of the GP proton density are in good agreement with those extracted from the experimental charge form factors. The corresponding surface diffuseness parameter values are also in reasonably good agreement with the experimental values with some exceptions. The mass number dependence of the diffraction radii and diffuseness parameters of the GP proton, neutron densities, and their average have been studied.

3 illus, 11 ref

002210   Villegas J E;Nunez N O;Gonzalez M P;Gonezalez E M;Vicent J L (Departamento Fisica Materiales Facultad CC Fisicas, Universidad Complutense 28040, Madrid, Spain, Email: jlvicent@fis.ucm.cs) : Experimental adiabatic vortex ratchet effect in Nb films with asymmetric pinning trap. Pramana J Phys 2006, 66(1), 289-94.

Nb films grown on top of an array of asymmetric pinning centers show a vortex ratchet effect. A net flow of vortices is induced when the vortex lattice is driven by fluctuating forces on an array of pinning centers without reflection symmetry. This effect occurs in the adiabatic regime and it could be mimiced only by reversible DC driven forces.

5 illus, 14 ref

002209   Togawa Y;Harada K;Akashi T;Kasai H;Matsuda T; Maeda A;Tonomura A (Frontier Res System, The Inst of Phys and Chem Res (RIKEN), Hatoyama, Saitama-350 0395, Japan) : Direct observation of rectified motion of vortices by lorentz microscopy. Pramana J Phys 2006, 66(1), 279-87.

Investigets the vortex dynamics for the 'ratchet' operation in a niobium superconductor via a direct imaging of Lorentz microscopy. Directly observe one-directional selective motion of field-gradient-driven vortices along fabricated channels. This results from the rectification of vortices in a spatially asymmetric potential under the oscillating magnetic field in a temporally symmetric manner. Based on the observation of the individual motion of vortices.The elementary process involved in this rectification.

4 illus, 24 ref

002208   Thakur A D;Banerjee S S;Higgins M J; Ramakrishnan S;Grover A K (DCMP&MS, Tata Inst of Fundamental Res, Mumbai-400 005) : Effect of pinning and driving force on the metastability effects in weakly pinned superconductors and the determination of spinodal line pertaining to order-disorder transition. Pramana J Phys 2006, 66(1), 159-77.

Vortex phase diagram showing different vortex phases for a typically weakly pinned specimen has been constructed via the AC susceptibility data in a crystal of 2H-NbSe₂ which shows the SMP and the PE anomalies. The phase space of coexisting weaker and stronger pinned regions has been identified. It can be bifurcated into two parts, where the order and disorder dominate, respectively. The former part continuously connects to the reentrant disordered vortex phase pertaining to the small bundle pinning regime, where the vortices are far apart, interaction effects are weak and the poly crystal line form of flux line lattice prevails.

6 illus, 42 ref

002207   Tamegai T;Aoki H;Matsui M;Tokunaga M (Dep of Appl Phys, The Univ of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan, Email: tamagai@ap.t.u_tokyo.ac.jp) : Bitter decoration and magneto-optical observations of vortex chains in high temperature superconductors. Pramana J Phys 2006, 66(1), 271-8.

In tilted magnetic fields, vortices in anisotropic superconductors form one-dimensional arrangements, called vortex chains. Visualized vortex chains by Bitter decoration and magneto-optical technique. The fundamental energy scale for the attractive interaction between pancake and Josephson vortices is evaluated by observing vortex chains under various conditions. Also explore now the vortex chains evolve when the large in-plane field is applied or when the anisotropy parameter of the system is changed.

4 illus, 17 ref

002206   Srinivasan R (NO, Raman Res Inst C.V. Raman Avenue, Sadashivanagar, Bangalore-560 080, Email: rsv@rri.res.in) : Vortices in Bose-Einstein condensates: a review of the experimental results. Pramana J Phys 2006, 66(1), 3-30.

Rotating dilute Boss-Einstein condensates (BEG) of alkali atoms offer a testing ground for theories of vortices in weakly interacting superfluids. In a rotating superfluid, quantised vortices, with a vorticity h/m, form above a critical velocity. Such vortice have been generated in BEC of alkali atoms by different techniques such as (a) wave function engineering of a two-component BEC, (b) decay of solitons, (c) rotation of a thermal cloud before cooling it below the condensation temperature, (d) stirring with an 'optical' spoon, (e) rotating a deformation in the anisotropic trap in which the condensate is trapped and (f) by creating Berry phase by adiabatically reversing the axial magnetic field. Since the core of a vortex is a fraction of a micrometer in diameter, it cannot be directiy imaged optically. The condensate with vortices is allowed to hallistically expand till the size increases by one order before the vortices are imaged. Surface wave spectroscopy and the change in aspect ratio of a rotating cloud are the other techniques used. Studies have been made on the creation and dynamics of single vortex and on systems with more than a hundred vortices. Results have been obtained on vortex hucleation, stability of vortex structures, nature of the vortex lattice and defects in such a lattice. Important results are: (a) evidence exists that vortex nucleation takes place by a surface mode instability; but this is not the only mechanism; (b) the vortex lattice is perfectly triangular right up to the edge; (c) in, the initial stages of rotation of the cloud a tangled web of vortices is seen; it takes a few hundred milliseconds before the vortices arrange themselves in a lattice; this time appears to be independent of temperature; (d) the decay of vortices appears to arise from the transfer of energy to the rotating thermal component and is dependent on temperature; (e) defects in the lattices such as dislocations and grain boundaries are seen; (f) transverse oscillations (Tkachenko modes) of the vortex lattice have been observed; and (g) giant vortices have been produced and discussed.

16 illus, 47 ref

002205   Simon C;Pautrat A;Goupil C;Scola J;Mathieu P; Brulet A;Ruyter A;Higgins M J;Bhattacharya S;Plessis D (Laboratoire CRISMAT CNRS-ENSICAEN F14050 Caen, , France, Email: simon@ensicaen.fr) : Why pinning by surface irregularities can explain the peak effect in transport properties and neutron diffraction results in NbSe2 and Bi-2212 crystals?. Pramana J Phys 2006, 66(1), 83-97.

Existence of a peak effect in transport properties (a maximum of the critical current as function of magnetic field) is a well-known but still intriguing feature of Type II superconductors such as NbSe₂ and Bi-2212. Using a model of pinning by surface irregularities in anisotropic superconductors, authors have developed a calculation of the critical current which allows estimating quantitatively the critical current in both the high critical current phase and the low critical current phase. The only adjustable parameter of this model is the angle of the vortices at the surface. The agreement between the measurements and the model is really very impressive. In this framework, the anomalous dynamical properties close to the peak effect is due to coexistence of two different vortex states with different critical currents. Recent neutron diffraction data in NbSe₂ crystals in the presence of transport current support this point of view.

8 illus, 14 ref

002204   Shibauchi T;Kawakami T;Terao Y;Suzuki M; Fldaum L Krusin (Dep of Electronic Sci and Engng, Kyoto Univ, Nishikyo-ku, Kyoto 605-8510, Japan, Email: shiba@kuee.kyoto-u.ac.jp) : Interlayer magnetotransport study in electron-doped Sm_2-xCexCuO_4-delta. Pramana J Phys 2006, 66(1), 305-12.

Vortex and pseudogap states in electron-doped Sm_2-xCe_xCuO_4-δ- (x <126> 0.14) are investigated by the inter layer transport in magnetic fields up to 45 T. To extract, intrinsic properties, fabricates small 30 nm-high mesa structures, sufficiently thin to be free of the recently reported partial decomposition problems. On cooling, the c-axis resistivity pc of the mesa structures reveals a semiconductive upturn above T_c, followed by a sharp superconducting transition at 20 K. When the magnetic field H is applied along the c-axis, pc(T) shows a parallel shift without significant broadening, as also observed in the hole-doped underdoped cuprates. Above the transition we observe negative magnetoresistance (MR), which can be attributed to the field suppression of the pseudo-gap, whose magnitude is as small as 38 K. The results in the x<126>-0.14 samples closely correspond to the inter layer transport behavior in the 'overdoped' regime of hole-doped Bi₂Sr₂CaCu₂O_8+y.

4 illus, 23 ref

002203   Sarkar S;Tomy C V;Thakur A D;Balakrishnan G; Paul D M;Ramakrishnan S;Grover A K (DCMP&MS, Tata Inst of Fundamental Res, Mumbai-400 005, Email: phy.ac.in;) : Pulverization of the flux line lattice, the phase coexistence and the spinodal temperature of the order-disorder transition in a weekly pinned crystal of Yb₃Rh₄Sn₁₃. Pramana J Phys 2006, 66(1), 179-92.

Studies metastability effects pertaining to the peak effect (PE) in critical current density (Jc) via isofield scans in AC susceptibility measurements in a weakly pinned single crystal of Yb₃Rh₄Sn₁₃ (T_c(0} ≈ 7.6 K). The order-disorder transition in this specimen proceeds in a multi-step manner. The phase coexistence regime between the onset temperature of the PE and the spinodal temperature {where metastability effects cease) seems to comprise two parts, where ordered and disordered regions dominate the bulk behavior, respectively. The PE line in the vortex phase diagram is argued to terminate at the low field end at a critical point in the elastic (Bragg) glass phase.

6 illus, 31 ref

002202   Sarkar S;Thakur A D;Tomy C V;Balakrishnan G; Paul D M;Ramakrishnan S;Grover A K (NO, Tata Inst of Fundamental Res, Mumbai-400 005, Email: iitb.ac.in;) : Critical points in the bragg glass phase of a weakly pinned crystal of Ca3Rh4Sn13. Pramana J Phys 2006, 66(1), 193-207.

New experimental data are presented on the scan rate dependence of the magnetization hysteresis width ΔM(H) (∞ critical current density JC(H)) in isothermal M-H scans in a weakly pinned single crystal of Ca₃Rh₄Sn₁₃, which displays second magnetization peak (SMP) anomaly as distinct from the peak effect (PE). Observes an interesting modulation in the field dependence of a parameter which purports to measure the dynamical annealing of the disordered bundles of vortices injected through the sample edges towards the destined equilibrium vortex state at a given H. These data, in conjunction with the earlier observations made while studying the thermomagnetic history dependence in JC(H) in tlie tracing of the minor hysteresis loops, imply that the partially disordered state heals towards the more ordered state between the peak field of the SMP anomaly and the onset field of the PE. The vortex phase diagram in the given crystal of Ca₃Rh₄Sn₁₃ has been updated in the context of the notion of the phase coexistence of the ordered and disordered regions between the onset field of the SMP anomaly and the spmodal line located just prior to the irreversibility line, A multi-critical point and a critical point in the (H, T) region of the Bragg glass phase have been marked in this phase diagram and the observed behavior is discussed in the light of recent data on multi-critical point in the vortex phase diagram in a single crystal of Nb.

6 illus, 37 ref

002201   Pasquini G;Bekeris V (Departamendo de Fisica Laboratorio de Bajas Temperaturas FCEN, , Universidad de Buenos Aires, CONICET, Email: pasquini@df.uba.ar) : Vortex lattice mobility and effective pinning potentials in the peak region in YBCO crystals. Pramana J Phys 2006, 66(1), 149-57.

The peak effect (PE) in the critical current density in both low and high temperature superconductors has been the subject of a large amount of experimental and theoretical work in the last few/several years. In the case of YBCO, crucial discussions describing a dynamic or a static picture are not settled. In that region of field and temperature the mobility of the vortex lattice (VL) is found to be dependent on the dynamical history, rtecently authors has reported evidence that the VL reorganizes and accesses to robust VL configurations (VLCs) with different effective pinning potential wells arising in response to different system histories. One of the keys to understand the nature of the PE is to investigate the VL behavior in the vicinity of the various VLCs in the region of the PE. The stability of these VLCs was investigated and it was found that they have distinct characteristic relaxation times, which may be related to elastic or plastic creep processes. Reviews some of these results and propose a scenario to describe the PE in YBCO crystals.

4 illus, 24 ref

002200   Okuma S (Res Cent for Low Temperature Phys, Tokyo Inst of Technol 2-12-1 Ohokayama Meguro-ku, Tokyo-152 8551, Japan, Email: sokuma@o.cc.titech.ac.jp) : Unusual vortex dynamics in the quantum-liquid phase of a-Mox-Si1-x films. Pramana J Phys 2006, 66(1), 261-9.

Finds the unusual vortex dynamics in the low-temperature liquid phase of amorphous Mo_xSi_1-x films by measuring the fluctuating component of the flux-flow voltage δV(t) about the average voltage. For the thick film, in which the quantum-vortex-liquid (QVL) phase has been well-determined in the field-temperature plane, δV(t) originating from the vortex motion is clearly visible in the QVL phase, where the distribution of δV(t) is anomalously asymmetric, implying large velocity and/or number fluctuations of driven vortices. For the thin film, in which the QVL phase has not been determined from the static transport measurements, similar unusual vortex motion is observed in nearly the same reduced-temperature regime. Suggest that vortex dynamics in the low-temperature liquid phase of thick and thin filtns is dominated by common physical mechanisms related to quantum-fluctuation effects.

5 illus, 41 ref

002199   Movshovich R;Bianchi A;Capan C;Pagliuso P G; Sarrao J L (Los Alamos Natn Lab Los Alamos, , New Mexico-87545, USA) : Possible fulde-ferrell-larkin-ovchinnikov inhomogeneous superconducting state in CeCoIn5. Pramana J Phys 2006, 66(1), 227-37.

Presents specific heat and thermal conductivity of the heavy fermion su perconductor CeCoIn₅ in the vicinity of the superconducting critical field H_c2, measured with magnetic field in the plane of this quasi-2D compound and at temperatures down to 50 mK. The superconducting phase diagram and the first order nature of the superconducting phase transition at high fields close to a critical field H_c2 indicate the importance of the Pauli limiting effect in CeCoIn₅. In the same range of magnetic field we observe a second specific heat anomaly within the superconducting state, and interpret it as a signature of a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) inhomogeneous superconducting state. In addition, the thermal conductivity data as a function of field display a kink at a field H_k below the superconducting critical field, which closely coincides with the low temperature anomaly in specific heat tentatively identified with the appearance of the FFLO superconducting state. The enhancement of thermal conductivity within the FFLO state calls for further theoretical investigations of the real space structure of the order parameter (and in particular, the structure of vortices} and of the thermal transport within the iuhomogeneous FFLO state.

6 illus, 35 ref

002198   Matsuda Y (Dep of Phys, Kyoto Univ, Kyoto-606-8581, Japan, Email: matsuda@scphys.kyoto-u.ac.jp) : Multiple superconducting phases in heavy fermion compounds PrOs₄Sb₁₂ and CeCoIn₅. Pramana J Phys 2006, 66(1), 239-46.

In recently discovered heavy fermion compounds, quasi-two-dimensional CeCoIn₅ and skutterudite PrOs₄Sb₁₂, multiple superconducting phases with different symmetries manifest themselves below T_c. The angle-resolved magnetothcrinal transport measurements revealed that in PrOs₄Sb₁₂ a novel change in the symmetry of the superconducting gap function occurs deep inside the superconducting state. The ultrasound velocity measurements revealed that in CeCoIn₅ the Fulde-Ferrel-Larkin-Ovchinikov (FFLO) phase, in which the order parameter is spatially modulated and has planar nodes aligned perpendicular to the vortices, appears at low temperature and high field. These results open up a new realm for the study of the superconductivity with multiple phases.

4 illus, 44 ref

002197   Li D;Rosenstein B;Lin P (Dep of Phys, Peking Univ, Beijing-100 871, People's Republic of China, Email: lipd_2000@hotmail.com) : Quantitative theory of thermal fluctuations and disorder in the vortex matter. Pramana J Phys 2006, 66(1), 99-111.

Metastable supercooled homogeneous vortex liquid state exists down to zero fluctuation temperature in systems of mutually repelling objects. The zero-temperature liquid state therefore serves as a (pseudo) 'fixed point' controlling the properties of vortex liquid below and even around the melting point. Based on this picture, a quantitative theory of vortex melting and glass transition in Type II superconductors in the framework of Ginzburg-Landau approach is presented. The melting line location is determined and magnetization and specific heat jumps are calculated. The point-like disorder shifts the line downwards and joins the order-disorder transition line. On the other hand, the disorder induces irreversible effects via replica symmetry breaking. The irre-versibility line can be calculated within the Gaussian variational method. Therefore, the generic phase diagram contains four phases divided by the irreversibility line and melting line: liquid, solid, vortex glass and Bragg glass. Compares various experimental results with the theoretical formula.

6 illus, 1 tables, 65 ref

002196   Kumar D;Gupta S;Basu S (Dep of Chem Engng, Indian Inst of Technol Delhi, New Delhi-110 016, Email: sbasu@chemical.iitd.ernet.in) : Prediction of surface tension of organic liquids using artificial neural networks. Indian chem Engr 2005, 47(4), 219-23.

The theoretical prediction of the surface tension of organic Compounds is required in many chemical engineering calculations. In view of this and due to lack of predictability of surface tension by available theoretical models, the capability of artificial neural network is tested for this purpose. A forward-feed back propagation neural network, based on the Levenberg-Marquardt optimization and gradient descent with momentum weight and bias method was used. The input parameters, e.g., density, refractive index and parachor, to the neural network were chosen from the previous studies on theoretical prediction of surface tension. The trained neural network predicted the surface tension of various polar, non-polar, saturated and unsaturated organic compounds at 20°C with a reasonable accuracy for the training data set (overall absolute percent deviation ([AAD%] 0.31) and for the test compounds (%AAD 3.24). These predictions are an improvement over various predictions from presently used models for the same set of compounds.

6 illus, 2 tables, 15 ref

002195   Klein U (NO, Johannes Kepler Universitat Linz Institut fur Theoretische Physik A-4, Austria, Email: ulf.klein@jku.at) : Antivortices due to competing orbital and paramagnetic pair-breaking effects. Pramana J Phys 2006, 66(1), 209-17.

Thermodynamically stable vortex-antivortex structures in a quasi-two-dimensional superconductor in a tilted magnetic field are predicted. For this geometry, both orbital and spin pair-breaking effects exist, with their relative strength depending on the tilt angle θ. The spectrum of possible states contains the ordinary vortex state (for large θ) and the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state (for θ = 0) as limits. The quasi-classical equations are solved near H_c2 for arbitrary θ and it is shown that stable states with co-existing vortices and antivortices exist in a small interval close to θ = 0. The results are compared with recent predictions of antivortices in mesoscopic samples.

3 illus, 25 ref

002194   Kalisky B;Shaulov A;Yeshurun Y (Dep of Phys, Inst of Superconductivity Bar-Ilan Univ, Ramat-Gan-52900, Israel, Email: yeshrun@mail.biu.ac.il) : Effect of sample size on the second magnetization peak in Bi₂Sr₂CaCuO₈+Delta at low temperatures. Pramana J Phys 2006, 66(1), 141-7.

Effects of sample size on the second magnetization peak (SMP) in Bi₂Sr₂CaCuO₈+δ crystals are observed at low temperatures, above the temperature where the SMP totally disappears. In particular, the onset of the SMP shifts to lower fields as the sample size decreases - a result that could be interpreted as a size effect in the order-disorder vortex matter phase transition. However, local magnetic measurements trace this effect to metastable disordered vortex states, revealing the same order-disorder transition induction in samples of different size.

6 illus, 31 ref

002193   Jaiswal Nagar D;Pal D;Eskildsen M R;Canfield P C;Takeya H;Ramakrishnan S;Grover A K (Dep of Condensed Matter Phys and Mater Sci, Tata Inst of Fundamental Res Homi Bhabha Rd, Colaba, Mumbai-400 005) : Vortex phase diagram studies in the weekly pinned single crystals of YNi₂B₂C and LuNi₂B₂C. Pramana J Phys 2006, 66(1), 113-29.

Presents a study of magnetization measurements performed on the single crystals of YNi₂B₂C and LuNi₂B₂C. For both the compounds, finds flux jumps in magnetisation values in the respective field regions, where the structural transitions in the flux line lattice symmetry have been reported in these systems via the small angle neutron scattering experiments. The magnetisation hysteresis loops and the AC susceptibility measurements show pronounced peak effect as well as second magnetisation peak anomaly for both YNi₂B₂C and LuNi₂B₂C. Based on these results, a vortex phase diagram has been constructed for YNi₂B₂C for H\c depicting different glassy phases of the vortex matter.

9 illus, 50 ref

002192   Hirata K (Superconducting Mater Cent, Natn Inst for Mater Sci 1-2-1 Sengen, Tsukuba-305-0047, Email: HIRATA.kazuto@nims.go.jp) : Maganetic phase diagram of josephson vortices in Bi₂Sr₂CaCu₂O₂+y. Pramana J Phys 2006, 66(1), 131-9.

Shows experimental results on magnetic phases of Joseplison vortices (JVs) in Bi₂Sr₂CaCu₂O_2+y obtained from the JV flow-resistance measurements. Periodic oscillations in the flow-resistance enable us to assign the phase of the long-range 3D ordered state, which was confirmed by the beating effect. Mades preliminary experiments on the doping effect to the JV magnetic phase. The doping effect is reflected not only in the lower boundary of 3D ordered phase, but also in the upper boundary. Above the upper boundary, the flow-resistance shows different behaviours, which may be related to the strength of the interlayer coupling of the JVs along the c-axis, and to the creation/annihilation of pancake vortex/ant i-vortex pairs, thermally and magnetically.

6 illus, 20 ref

002191   Gupta A K;Cretinon L;Pannetier B;Courtois H (Dep of Phys, Indian Inst of Technol, Kanpur, Kanpur-208 016, Email: anjankg@iitk.ac.in) : Anomalous density of states in hybrid normal metal-superconductor bilayers. Pramana J Phys 2006, 66(1), 251-9.

In contact with a superconductor, the Andreev reflection of the electrons locally modifies the N metal electronic properties, including the local density of states (LDOS). Authors has investigated the LDOS in superconductor-normal metal (Nb-Au) bilayers using a very low temperature (60 mK) STM on the normal metal side. High resolution tunneling spectra measured on the Au surface show a clear proximity effect with an energy gap of reduced amplitude compared to the bulk Nb gap. The dependence of this mini-gap width with the normal metal thickness is discussed in terms of the Thouless energy. Within the mini-gap, the density of states does not reach zero and shows clear sub-gap features. Compares the experimental spectra with the well-established quasi-classicai theory.

5 illus, 22 ref

002190   Elbaum L Krusin;Shibauchi T;Blatter C (IBM T. J. Watson Res Cent Yorktown Heights, , New York-10598, USA, Email: krusin@us.ibm.com) : Zeeman and orbital limiting magnetic fields in cuprates: the pseudogap connection. Pramana J Phys 2006, 66(1), 219-25.

In cuprates, in a view where pairing correlations set in at the pseudogap energy scale T* and acquire global coherence at a lower temperature T_c, the region T_c ≤ T ≤ T* is a vast fluctuation regime. T_c and T* vary differently with doping and the question remains about the doping trends of the relevant magnetic field scales: the field H_c2 bounding the superconducting response and the pseudogap closing field H_pg. In-plane thermal (Nernst) and our interlayer (tunneling) transport experiments in Bi₂Sr₂CaCu₂O_8+y report hugely different limiting magnetic fields. Here, based on pairing (and the uncertainty principle) combined with the definitions of the Zeeman energy and the magnetic length, shows that both fields convert to the same pseudogap scale T* upon transformation as orbital and Zeeman critical fields, respectively. The region of superconducting coherence is confined to the 'dome' that coincides with the usual unique upper critical field H_c2 on the strongly overdoped side. That the distinctly different orbital and the Zeeman limiting fields can co-exist awing to charge and spin degrees of freedom separated to different parts of the strongly anisotropic Fermi surface.

4 illus, 24 ref

002189   Doria M M;De A R;Romaguera C;Morgado W A M (NO, Instituto de Fisica Universidade Fedl do Rio de Janeiro, C.P. 68528, Email: mmd@if.ufrj.br) : Three-dimensional Ginzburg-Landau simulation of a vortex line displaced by a zigzag of pinning spheres. Pramana J Phys 2006, 66(1), 295-304.

A vortex line is shaped by a zigzag of pinning centers and we study here how far the stretched vortex line is able to follow this path. The pinning center is described by an insulating sphere of coherence length size such that in its surface the de Gennes boundary condition applies. Calculates the free energy density of this system in the framework of the Ginzburg-Landau theory and study the critical displacement beyond which the vortex line is detached from the pinning center.

12 illus, 17 ref

002188   Cozzini M (Dipartimendo di Fisica, Universita di Trento and BEC Cent CNR-INFM, I-38050 Povo, Italy, Email: cozzini@science.unitn.it) : Diffused vorticity approach to the oscillations of a rotating Bose-Einstein condesate confined in a harmonic plus quartic trap. Pramana J Phys 2006, 66(1), 31-42.

The collective modes of a rotating Bose-Einstein condensate confined in an attractive quadratic plus quartic trap are investigated. Assuming the presence of a large number of vortices we apply the diffused vorticity approach to the system. Uses the sum rule technique for the calculation of collective frequencies, comparing the results with the numerical solution of the linearized hydro dynamic equations. Numerical solutions also show the existence of low-frequency multipole modes which are interpreted as vortex oscillations.

3 illus, 29 ref

002187   Brandt E H (NO, Max-Planck-Institut fur Metallforschung D-70506 Stuttgart, Germany, Email: ehb@mpg.de) : Vortices in superconducting bulk, films and SQUIDs. Pramana J Phys 2006, 66(1), 67-81.

Properties of the ideal periodic vortex lattice in bulk superconductors and in films of any thickness can be calculated from Ginzburg-Landau theory by an iteration method using Fourier series. The London theory yields general analytic expressions for the magnetic field and energy of arbitrary arrangements of straight or curved vortex lines. The elasticity of the vortex lattice is highly nonlocal. The magnetic response of superconductors of realistic shapes like thin and thick strips and disks or thin rectangular plates or films, containing pinned vortices, can be computed within continuum theory by solving an integral equation. A useful example is a thin square with a central hole and a radial slit, used as superconducting quantum interference device (SQUID).

8 illus, 40 ref

002186   Benetatos P;Marchetti M Cristina (NO, Hahn-Meitner-Institut A bteilung Theoretische Physik (SF5) Glienicker, D-14109 Berlin , Germany) : Weak point disorder in strongly fluctuating flux-line liquids. Pramana J Phys 2006, 66(1), 55-65.

Considers the effect of weak uncorrelated quenched disorder (point defects) on a strongly flctuating flux-liue liquid. Uses a hydrodynamic model which is based on mapping the flux-line system onto a quantum liquid of relativistic charged bosons in 2 + 1 dimensions [P Benetatos and M C Marchetti, Phys. Rev. B64, 054518 (2001)]. In this model, flux lines are allowed to be arbitrarily curved and can even form closed loops. Point defects can be scalar or polar. In the latter case, the direction of their dtpole moments can be random or correlated. Within the Gaussian approximation of our hydrodynamic model, author has calculated disorder-induced corrections to the correlation functions of the flux-line fields and the elastic moduli of the flux-line liquid. Finds that scalar disorder enhances loop nucleation, and polar (magnetic) defects decrease the tilt modulus.

33 ref

002185   Banerjee S S (Dep of Phys, Indian Inst of Technol Kanpur, Kanpur-208-016, Email: satyajit@iitk.ac.in) : Melting of heterogenous vortex matter: the vortex 'nanoliquid'. Pramana J Phys 2006, 66(1), 43-54.

Disorder and porosity arc parameters that strongly influence the physical behavior of materials, including their mechanical, electrical, magnetic and optical properties. Vortices in superconductors can provide important insight into the effects of disorder because their size is comparable to characteristic sizes of nano fabricated structures. Here author has presented experimental evidence for a novel form of vortex matter that consists of interconnected uanodroplets of vortex liquid caged in the pores of a solid vortex structure, like a liquid permeated into a nanoporous solid skeleton. Nanoporous skeleton is formed by vortites pinned by correlated disorder created by high-energy heavy ion irradiation. By sweeping the applied magnetic field, the number of vortices in the nanodroplets is varied continuously from a few to several hundred. Upon cooling, the caged nanodroplets freeze into ordered nanocrystals through either a first-order or a continuous transition, whereas at high temperatures a uniform liquid phase is formed upon delocalization-induced melting of the solid skeleton. This new vortex nanoliquid displays unique properties and symmetries that are distinct from both solid and liquid phases.

5 illus, 56 ref

002184   Awana V P S;Kishan H (Natn Phys Lab, Dr. K.S. Krishnan Marg, New Delhi-110 012, Email: awana@mail.nplindia.ernet.in ) : Spontaneous vortex phase (SVP) of ruthenocuprate high Tc magneto-superconductors. Pramana J Phys 2006, 66(1), 247-50.

The Ru_0.9Sr₂YCu_2.1O_7.9 compound synthesized by HPHT (high pressure high temperature) solid-state reaction route exhibits bulk superconductivity below 30 K Also the Ru-spins are ordered magnetically above 143 K, with a ferromagnetic component at 5 K. Low field (<60>1000 Oe) M vs. H plots show that both the superconducting and ferromagnetic components are present in the compound at 5 K. At low temperatures, the compouud though remains in spontaneous vortex phase, its M vs. H hysteresis loop is symmetric instead of the theoretically expected asymmetric one. The results cast doubts on either theoretical model or the intrinsic nature of ferromagnetic superconductivity in studied ruthenate.

2 illus, 7 ref

001102   Wolf G Y (NO, KRKI RMKI, 1525 Budapest, P.O.Box 49, Hungary, Email: wolf@rmki.kfki.hu) : Vector mesons in matter. Pramana J Phys 2006, 66(4), 781-90.

One consequence of the chiral restoration is the mixing of parity partners. Looks for a possible signature of the mixing of vector and axial vector mesons in heavy-ion collisions. An experimental method for its observation has been suggested. The dynamical evolution of the heavy-ion collision is described by a transport equation of QMD-type evolving nucleons, N* and Δ resonances, Λ's and ∑ baryons, and furthermore, π'S, η'S p's σ's ω's and kaons with their isospin degrees of freedom. The input cross-sections and resonance parameters of the model are fitted to the available nucleon-nucleon and pion-nucleon cross-sections.

6 illus, 1 table, 12 ref

001101   Vijayaragavan A R;Chari R;Oak S M (Phys Dep, Anna Univ, Chennai-600 025) : Achieving high signal-to-noise ratio in transient reflectivity measurements. Indian J pure appl Phys 2006, 44(4), 330-3.

Transient reflectivity measurements using ultrashort pulse pump-probe techniques can provide very useful information on fast carrier dynamics in semiconductors. Several non-trivial problems encountered in measuring reflectivity changes have been described. These changes can be very small (ΔR/R <126> 10^-3 or less) and hence measuring these small changes is not straightforward. The possible solutions in overcoming such problems have been described. Some preliminary results on a GaAs thin film have also been presented.

3 illus, 1 table, 4 ref

001100   Varghese T;Mathew P;Balakrishna K M;Siddappa K (Dept of Phys, Nirmala Coll, Muvattupuzha, Kerala-696 661, Email: surajthomas@sancharnet.in) : Compton profile of zinc. Sci Soc 2004, 2(2), 49-55.

The electron momentum distribution and Compton profiles of Zn has been measured using HPGe photon detector. The target atoms were excited by means of 59.54 keV gamma rays from Am-241. The measurements were carried out on a high purity thin elemental foil. The data were recorded and analyzed in a 4K multichannel analyzer. The data duly corrected for instrumental resolution effects, sample absorption, energy dependence of the differential Compton cross-section and double scattering are presented along with theoretical profiles.

3 illus, 1 tables, 8 ref

001099   Varghese T;Mathew P (Dept of Phys, Nirmala Coll, Muvattupuzha,-696 661) : Aerogel. Sci Soc 2004, 2(2), 77-80.

^ssc1 illus, 1 table

001098   Unnikrishnan N V (NO, Sch of Pure and Appl Phys M.G. Univ, Kottayam, Kerala) : Diode lasers. Sci Soc 2004, 2(2), 5-16.

Brief history of diode lasers, and advantages of diode lasers over other lasers are described. The theory of DH lasers, quantum well lasers, high power diode lasers, quantum wire and quantum dot lasers and Quantum cascade lasers are also discussed. The diode lasers are widely used in laser printers, CD-players, fiber optic communication etc.

^iia4 illus, 20 ref

001097   Tyagi A;Singh R;Bansal M K;Soni R K (Phys Dep, Bharat Inst of Technol, Meerut-250 103) : Optical study and synthesis of porous silicon nanostructures. Indian J pure appl Phys 2006, 44(4), 312-14.

Porous silicon nanostructures have been generated using laser assisted etching (photochemical etching). The shape and size of the nanostructures obtained, depend on the wavelength used. The dependence of Raman shift and photoluminescence on the shape and size of nanostructures was studied.

4 illus, 15 ref

001096   Suresh Chandra;Musrif P G;Shinde S V (Sch of Phys Sci, S.R.T.M. Univ, Nanded-431 606, Email: sch@iucaa.ernet.in) : Anomalous absorption in H₂CO molecule. Bull Astr Soc India 2006, 34(1), 11-19.

Snyder et al. (1969) detected H₂CO through its transition 1₁₀-1₁₁ at 4.829 GHz in absorption in the interstellar medium in a number of galactic and extragalactic sources (M17, W3, W3(OH position), W49, NGC 2024, DR 21, W43, W44, W51, Sgr A, Sgr B2, W33, NGC 6334, gas A, and 3C 123). This transition of H₂CO was found in anomalous absorption by Palmer et al. (1969) in the direction of four dark nebulae. In some objects, this transition has however been detected in emission and even as a maser line (Forster et al. 1980; Whiteoak et al. 1983). Evans et al. (1970) reported detection of H₂CO molecule through its transition 2₁₁ - 2₁₂ at 14.488 GHz in absorption in some cosmic objects. This transition was also found in anomalous absorption by Evans et al. (1975). Since the transition 1₁₀ - 1₁₁ is considered as a unique probe of high density gas at low temperature, the study of H₂CO in cosmic objects is of great importance. Garrison et al. (1975) investigated the problem of anomalous absorption of 1₁₀ - 1₁₁ and 2₁₁ -2₁₂ transitions of H₂CO where they accounted for 8 energy levels connected by 10 radiative transitions and considered a kinetic temperature of 5 - 20 K. They found weak anomalous absorption of 1₁₀ - 1₁₁ and 2₁₁ - 2₁₂ transitions of H₂CO. Investigated the transfer of radiation in H₂CO accounting 22 rotational energy levels connected by 47 radiative transitions in ground vibrational and ground electronic state. Further, considered a kinetic temperature of 10 - 40 K, as the kinetic temperature in some regions may be rather high. Thus, the work may be considered as an extension of the work of Garrison et al. (1975) where the investigation is carried out in more detail. Obtained remarkable anomalous absorption of 1₁₀ - 1₁₁, 2₁₁ - 2₁₂ and 3₁₂ - 3₁₃ transitions of H₂CO. In order to include a large number of cosmic objects, where H₂CO may be found, parameters in investigation are varied over wide ranges.

3 illus, 1 table, 10 ref

001095   Srivastava S K;Singh L K (Phys and Electron Dep, Dr. Ram Manohar Lohia Avadh Univ, Faizabad-224 001) : Spectral distribution and enhancement studies of (ZnS+HgO) base electroluminophor. Indian J pure appl Phys 2006, 44(4), 320-4.

The enhancement effect of dielectric dispersed double band emitting (ZnS+HgO):Cu,Mn(H) electroluminescent material has been investigated under the concurrent excitation of ac fields and 3650 Angstrom UV-rdiation. The emissions in yellow region were found to show relatively larger enhancement than that in case of green emission. The instantaneous behaviour of the individual peaks (green and yellow) was critically recorded and was observed that both the emissions isolately behave almost similarly and exhibit an exponential decay or rise before attaining the saturation value. The maximum enhancement is always found to be less than 4/3.

7 illus, 14 ref

001094   Singh S K;Athar M S;Ahmad S (Dep of Phys, Aligarh Muslim Univ, Aligarh 202 002, Email: pht13sks@rediffmail.com) : Weak pion production from nuclei. Pramana J Phys 2006, 66(4), 689-701.

The charged current pion production induced by neutrinos in ¹²C, ¹⁶O and ⁵⁶Fe nuclei has been studied. The calculations have been done for the coherent as well as the incoherent processes assuming Δ dominance and takes into account the effect of Pauli blocking, Fermi motion and the renormalization of Δ in the nuclear medium. The pion absorption effects have also been taken into account.

6 illus, 1 table, 23 ref

001093   Shyam R (NO, Saha Inst of Nuclear Phys, 1/AF, Bidhan Nagar, Kolkata-700 064, Email: radhey.shyam@saha.ac.in) : Strangeness production in proton-proton and proton-nucleus collisions. Pramana J Phys 2006, 66(4), 765-80.

Discuss the investigation of the strange meson production in proton-proton (pp) and proton-nucleus (pA) reactions within an effective Lagrangian model. The kaon production proceeds mainly via excitations of N*(1650), N*(1710), and N*(1720) resonant intermediate nucleonic states, in the collision of two initial state nucleons. Therefore, the strangeness production is expected to provide information about the resonances lying at higher excitation energies. For beam energies very close to the kaon production threshold the hyperon-proton final state interaction effects are quite important. Thus, these studies provide a check on the models of hyperon-nucleon interactions. The in-medium production of kaons shows strong sensitivity to the self-energies of the intermediate mesons.

9 illus, 59 ref

001092   Sharma V R;Bhosale S J;Kedare S B;Nayak J K (Dep of Mechanical Engng Energy Systems Engng, Indian Inst of Technol Bombay, Powai, Mumbai-400 076, Email: sbkedare@iitb.ac.in) : A simple method to determine optical quality of paraboloid concentrating solar thermal collector. SESI Jl 2005, 15(2), 21-7.

A solar concentrator can be used for medium temperature industrial process heat applications and in solar thermal power plants. A point focusing solar collector forms a flux distribution in two spatial dimensions at the focal plane. A tool for analysing the flux distribution can be of great help to know the optical quality of the collector. Experiments need to be carried out in the focal region of the concentrating collector to know the radiation flux as well as its spatial distribution. Usually these quantities are measured by flux mapping techniques. These methods can provide accurate results, but the equipment is specialised and costly. An indirect and simple method to estimate optical quality parameters like focus size, optical radiation on receiver mouth and optical efficiency is proposed. Field tests were conducted based on the proposed method on 160 m² solar concentrator at Latur, Maharashtra installed for milk pasteurisation.

6 illus, 1 table, 5 ref

001091   Sharma R K;Sharma Y K (Phys Dep, Univ of Raj, Jaipur-302 004) : Synthesis, XRD and <. Indian J pure appl Phys 2006, 44(4), 325-9.

The synthesis of the polycrystalline Fe_1-xMn_xSb₂ alloys for 0.0 ≤ x ≤ 0.2 has been investigated X-ray powder diffraction (XRD) patterns of three specimens revealed the formation of single phase orthorhombic crystal structure. Lattice parameters and unit cell volume increase with the increase in Mn concentration. ⁵⁷Fe Mossbauer spectra measured for all the three specimens at 300K were analyzed in terms of a single quadrupole split doublet revealing paramagnetic character at this temperature.

3 illus, 1 table, 14 ref

001090   Sankar U;Kingson Solomon Jeevaraj A;Thenappan T (Phys Dep, Alagappa Univ, Karaikudi, Tamilnadu) : Dielectric studies of H-bonded complexes of benzamide and nicotinamide with alcohols. Indian J pure appl Phys 2006, 44(4), 339-44.

The hydrogen-bonded complexes formed by benzamide and nicotinamide with alcohols in 1, 4-dioxan were studied at 303 K. The following alcohols were used: 2-butoxy ethanol, 2-ethyl hexanol, hexan-1-ol and isopropanol. The dipole moments of the complexes were determined using Huyskens method. The excess dipole moments of the complexes were obtained from bond angle data. The results show the domination of polarization effects and the non-feasibility of higher order complexations.

2 illus, 3 tables, 24 ref

001089   Ranita U;Arunkumar Sharma B;Nabadwip Singh S (Phys Dep, Manipur Univ, Imphal-795 003) : Application of computerised glow curve deconvolution to determine the spectroscopy of traps in KCl. Indian J pure appl Phys 2006, 44(4), 308-11.

Computerised Glow Curve Deconvolution (CGCD) of a semiconducting/insulating material in principle is expected to provide its trap-spectroscopy, provided the deconvolution passes the goodness-of-fit test. The trap-spectroscopy of KCl by deconvoluting its glow curve has been provided. The reason for the abnormal values of trapping parameters reported in literature is critically discussed keeping this present finding in mind.

2 illus, 1 table, 23 ref