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Chalcogenide Letters 04/2012; · 0.83 Impact Factor
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Chalcogenide Letters 04/2012; · 0.83 Impact Factor
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Chalcogenide Letters 03/2012; · 0.83 Impact Factor
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ABSTRACT: Nanocrystals of copper indium disulphide (CuInS 2) were synthesized by a solvo-thermal method. The structure, morphology and non-isothermal crystallization kinetic behavior of samples were investigated using X-ray diffraction, field emission scanning electron mi-croscopy, field emission transmission electron microscopy, thermogravimetric analysis and differential thermal analysis techniques. Non-isothermal measurements at different heating rates were carried out and the crystallization kinetics of samples were analyzed using the most reliable non-isothermal kinetic methods. The kinetic parameters such as glass transition temperature, thermal stability, activation energy, Avrami exponent etc. were evaluated.
M A T E R I A L S C H A R A C T E R I Z A T I O N. 01/2012;
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ABSTRACT: Nanocrystalline thin films of CuInS 2 were grown onto ultra clean glass substrates using the spray pyrolysis technique. The films were characterized by X-ray diffraction, field emission scanning electron microscopy, field emission transmission electron microscopy, high resolution transmission electron microscopy, energy dispersive X-ray spectroscopy and resistivity measurement. XRD pattern, SEM and TEM micrographs show that the films grown at about 300 °C are made up of single phase nano-sized (12–15 nm) particles of CuInS 2 . Using Williamson–Hall equation, crystallite size and lattice strain of the film were estimated with the broadening of XRD peaks. EDX of nanoparticles dispersion confirmed the presence of elemental CuInS 2 and no peaks of impurity have been detected. The temperature dependence of resistivity of CuInS 2 thin films, determined in the temperature range of 100–300 K, exhibits their semiconducting behavior. The films showed the activated variable range hopping (VRH) in the localized states near the Fermi level.
Materials Letters 12/2011; · 2.31 Impact Factor
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ABSTRACT: Nuclei at both the neutron- and proton-drip lines are studied. In the
cluster-core model, the halo-structure of all the observed and proposed cases
of neutron- or proton-halos is investigated in terms of simple potential energy
surfaces calculated as the sum of binding energies, Coulomb repulsion, nuclear
proximity attraction and the centrifugal potential for all the possible
cluster+core configurations of a nucleus. The clusters of neutrons and protons
are taken to be unbound, with additional Coulomb energy added for
proton-clusters. The model predictions agree with the available experimental
studies but show some differences with the nucleon separation energy
hypothesis, particularly for proton-halo nuclei. Of particular interest are the
halo-structures of $^{11}N$ and $^{20}Mg$. The calculated potential energy
surfaces are also useful to identify the new magic numbers and molecular
structures in exotic nuclei. In particular, N=6 is a possible new magic number
for very neutron-deficient nuclei, but Z=N=2 and Z=8 seem to remain magic even
for such nuclei, near the drip line.
11/2011;
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ABSTRACT: The $\alpha$-decay chain of $^{293}$118, first proposed in the Berkeley cold
fusion experiment $^{208}$Pb($^{86}$Kr,1n) and now retracted, is calculated by
using the preformed cluster model (PCM) of one of us (RKG). Also, the possible
branchings of $\alpha$-particles to heavier cluster decays of all the parents
in this chain are calculated for the first time. The calculated Q-values,
penetrabilities and preformation factors for $\alpha$-decays suggest that the
$^{285}$114 nucleus with Z=114, N=171 is a magic nucleus, either due to the
magicity of Z=114, or of N=172 or of both. The N=172 is proposed to be a magic
number in certain relativistic mean-field calculations, but with Z=120. The
calculated cluster decays point to new interesting possibilities of $^{14}$C
decay of the $^{281}$112 parent, giving rise to a (reasonably) deformed Z=106,
N=161, $^{267}$106 daughter (N=162 being now established as the deformed magic
shell) or to a doubly magic $^{48}$Ca cluster emitted from any of the parent
nucleus in the $\alpha$-decay chain. Apparently, these are exciting new
directions for future experiments.
11/2011;
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Applied Surface Science 07/2011; · 2.10 Impact Factor
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Nanoscale Research Letters 06/2011; · 2.73 Impact Factor
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ABSTRACT: ABSTRACT: This work reports the preparation and characterization of silver nanoparticles synthesized through wet chemical solution method and of silver films deposited by dip-coating method. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), field emission transmission electron microscopy (FETEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and energy dispersive spectroscopy (EDX) have been used to characterize the prepared silver nanoparticles and thin film. The morphology and crystal structure of silver nanoparticles have been determined by FESEM, HRTEM, and FETEM. The average grain size of silver nanoparticles is found to be 17.5 nm. The peaks in XRD pattern are in good agreement with that of face-centered-cubic form of metallic silver. TGA/DTA results confirmed the weight loss and the exothermic reaction due to desorption of chemisorbed water. The temperature dependence of resistivity of silver thin film, determined in the temperature range of 100-300 K, exhibit semiconducting behavior of the sample. The sample shows the activated variable range hopping in the localized states near the Fermi level.
Nanoscale Research Letters 06/2011; 6:434. · 2.73 Impact Factor
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ABSTRACT: The halo structure of a light nucleus is shown to be associated with the closed shell effects of its core nucleus, and new magic numbers at N = 6 and 14 or 16 and/or Z = 6 and 14 are predicted on the basis of potential energy surfaces calculated within the cluster-core model. Whereas the old known magic numbers are found relevant for core nuclei near or not too far from the β-stability line, the above noted new magic numbers play their role for core nuclei near the drip lines. This result has apparent consequences for the spin–orbit interaction in exotic light nuclei.
Journal of Physics G Nuclear and Particle Physics 02/2006; 32(4):565. · 4.18 Impact Factor
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ABSTRACT: The α-decay chain of 293118, first proposed in the Berkeley cold fusion experiment 208Pb(86Kr, 1n) and now retracted, is calculated by using the preformed cluster model (PCM) of one of the authors (RKG). Also, the possible branchings of α-decays to heavier cluster decays of all the parents in this chain are calculated for the first time. The calculated Q-values, penetrabilities and preformation factors for α-decays suggest that the 285114 nucleus with Z = 114, N = 171 is a magic nucleus, either due to the magicity of Z = 114, or N = 172 or both. The N = 172 is proposed to be a magic number in certain relativistic mean-field calculations, but with Z = 120. The calculated cluster decays point to new interesting possibilities of 14C decay of the 281112 parent, giving rise to a (reasonably) deformed Z = 106, N = 161, 267106 daughter (N = 162 being now established as the deformed magic shell) or to a doubly magic 48Ca cluster emitted from any of the parent nucleus in the α-decay chain. Apparently, these are exciting new directions for future experiments.
Journal of Physics G Nuclear and Particle Physics 10/2002; 28(11):2875. · 4.18 Impact Factor
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