http://nopr.niscair.res.in/handle/123456789/13921 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/14006 Title: Study of structural property of <i style="">n</i>-type indium antimonide thin films <br/> <br/>Authors: Vishwakarma, S R; Verma, A K; Tripathi, R S N; Das, S; Rahul <br/> <br/>Abstract: In present study, the <i style="">n-</i>type indium antimonide (InSb) thin films of thickness 300 nm were deposited on glass substrate at room temperature under the high vacuum ~10^-5 torr using starting materials. The starting materials have been prepared under vacuum ~10^-5 torr in vacuum coating unit using indium (99.999%) and antimony (99.999%) metal powder as source materials with various non-stoichiometric composition as In₁_-xSb_x (0.2 < <i style="">x</i>< 0.4). The Energy Dispersive Analysis of X-rays (EDAX) measurement provides the information of chemical composition (In/Sb) in thin films. X-ray diffraction studies of starting materials and thin films confirmed the formation of InSb with polycrystallinity and orientation of crystallites along the (111) and (220) planes. The surface morphological study of thin films by scanning electron microscope reveals the crystalline nature which was found to be in good agreement with the XRD crystallinity analysis. The particle size (<i style="">D</i>), dislocation density (δ) and strain (<i style="">ε</i>) have been evaluated using XRD data for the starting materials and thin films. It is observed from X-ray diffraction patterns and scanning electron micrographs that particle size, dislocation density and strain are changing with composition ratio (In/Sb) in starting materials and their thin films. <br/> <br/>Page(s): 339-346 Sat, 28 Apr 2012 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/14005 Title: Optical and invitro bioactive properties of sodium silicate glasses <br/> <br/>Authors: Kumar, Vishal; Tyagi, Sachin; Singh, K <br/> <br/>Abstract: Sodium silicate based glasses have been synthesized by melt quenching technique. The surface reactivity of resultant glasses has been analyzed by immersion studies in simulated body fluid solution (SBF) for different time duration. The formation of hydroxyapatite layer has been studied through weight change (loss/ gain) of glass sample and change in <i style="">p</i>H of SBF solution. The addition of Al₂O₃ instead of P₂O₅in sodium silicate glasses increases the durability of glasses in SBF solution. The optical band gap decreases with increase of sodium oxide content with<b style=""> </b>soaking time of glass in SBF. <br/> <br/>Page(s): 335-338 Sat, 28 Apr 2012 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/14004 Title: Effect of size on cohesive energy, melting temperature and Debye temperature of nanomaterials <br/> <br/>Authors: Kumar, Raghuvesh; Kumar, Munish <br/> <br/>Abstract: A simple model has been used to study the size dependence of cohesive energy, melting temperature and Debye temperature. We have considered W, Ag, Al, Co and Au for the study of size dependence of cohesive energy and Al, Au, Ag, Zn, Bi for size dependence of melting temperature. The results obtained are compared with the available experimental data. A good agreement between theory and experiment encouraged the authors to extend the model to study the size dependence of Debye temperature. The results obtained for the size dependence of the Debye temperature are found to be in good agreement with the experimental data. This supports the validity of the model developed. <br/> <br/>Page(s): 329-334 Sat, 28 Apr 2012 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/14003 Title: Effect of 100 MeV Ni⁸⁺ ion irradiation on nanocrystalline PbS <br/> <br/>Authors: Choudhury, N; Singh, F; Sarma, B K <br/> <br/>Abstract: Nanocrystalline PbS prepared onto glass substrates by chemical bath deposition technique are irradiated with 100 MeV Ni⁸⁺ ion beams with different fluences from 1´10¹¹ to 1´10¹³ ions cm⁻². Analysis of the samples by X-ray diffraction show increase of average grain size from 11 nm for the pristine samples to 17 nm for the samples irradiated with 1´10¹¹ ions cm^-2. The grain size remains constant at higher fluences. The UV-visible optical absorption measurement also show that band gap of nanocrystalline PbS decreases from 1.9 eV for the pristine samples to 1.7 eV for the samples irradiated with fluences of 1´10¹¹ ions cm⁻²and then remains almost constant. It is observed from photoluminescence (PL) study that the PL intensity increases for irradiated samples with minimum intensity for pristine sample. <br/> <br/>Page(s): 325-328 Sat, 28 Apr 2012 22:58:59 GMT