Browsing by Author "Vandita Rao"
Now showing 1 - 5 of 5
- Results Per Page
- Sort Options
PublicationArticle Crystallization kinetics and Avrami index of Sb-doped Se–Te–Sn chalcogenide glasses(Taylor and Francis Ltd., 2018) D.K. Dwivedi; Vandita Rao; N. Mehta; N. ChandelBulk amorphous samples of Sb-substituted Se78 − xTe20Sn2Sbx (0 < x < 6) have been prepared using melt quench technique. The structure of Se78− xTe20Sn2Sbx (x = 0, 2, 4, 6) glassy alloys has been investigated using X-ray diffraction technique. Calorimetric studies of the prepared samples have been performed under non-isothermal conditions using differential scanning calorimetry (DSC) and glass transition temperature as well as crystallization temperature has been evaluated using DSC scans. The activation energy of crystallization kinetics (Ec) has been determined using model-free approaches such as Kissinger, Ozawa, Tang and Starink methods. The Avrami index (n) and frequency factor (Ko) have been calculated by Matusita and Augis–Benett method. © 2018 Informa UK Limited, trading as Taylor & Francis Group.PublicationArticle Effect of antimony on glass transition and thermal stability of Se78−xTe18Sn2Sbx (x = 0, 2, 4 and 6 at.%) multicomponent glassy alloys(Springer Netherlands, 2018) Vandita Rao; N. Chandel; N. Mehta; D.K. DwivediMulticomponent glassy alloys Se78−xTe18Sn2Sbx (x = 0, 2, 4 and 6) have been synthesized using melt quench technique. The prepared samples have been characterized by X-ray diffraction technique and differential scanning calorimetry (DSC). Glass transition kinetics of Se78−xTe18Sn2Sbx (x = 0, 2, 4 and 6 at.%) glassy alloys has been examined using DSC. DSC runs have been recorded at different heating rates (5, 10, 15 and 20 K min−1) for each sample under investigation. Heating rate dependence of glass transition temperature (Tg) has been studied using Lasocka empirical relation. The activation energy of glass transition has been evaluated using Kissinger and Moynihan’s relation. The effect of antimony concentration on glass transition temperature and activation energy has been investigated in the prepared samples. Glass-forming ability and thermal stability of Se78−xTe18Sn2Sbx (x = 0, 2, 4 and 6) glassy alloys have been monitored through the evaluation of thermal stability using Dietzal relation, Hurby parameter, and Saad and Poulin parameter. The above-mentioned parameters are found to be compositionally dependent, which indicates that among the studied glass samples the stability is maximum for Sb at 2% content. © 2018, Akadémiai Kiadó, Budapest, Hungary.PublicationArticle Effect of Sb incorporation on thermo-mechanical properties of amorphous Se-Te-Sn alloys(Institute of Physics Publishing, 2018) Vandita Rao; N. Mehta; Amit Kumar; D.K. DwivediIn present paper, bulk Se78-xTe20Sn2Sbx (x = 0, 2, 4 & 6) amorphous alloys were developed by melt quench technique. The synthesized samples were characterized by means of XRD and DSC techniques for structural and phase transformation analysis respectively. Hardness behavior was investigated by calculating Vickers hardness number and other thermo-mechanical parameters to examine the effect of Sb in Se-Te-Sn parent alloy. © 2018 IOP Publishing Ltd.PublicationArticle Investigation of Some Physico-Chemical Properties in Multi-Component Se–Te–Sn–Sb (0 ≤ x ≤ 6) Quaternary Chalcogenide Glassy System(Pleiades Publishing, 2018) Vandita Rao; Pooja Lohia; N. Mehta; D.K. DwivediAbstract: In the present work we report physico-chemical properties in novel Se78 – xTe20Sn2Sbx (x = 0, 2, 4 and 6) glassy system prepared by melt quench technique. Various physico-chemical properties such as co-ordination number, lone pair of electrons, number of constraints, density, molar volume, compactness, mean bond energy, cohesive energy, glass transition temperature and covalence character has been estimated. The compositional dependence of aforesaid physico-chemical properties has been investigated. It has been observed that average number of constraints, mean bond energy, glass transition temperature are found to increase where as number of lone pair of electrons and electro negativity decreases with increases of Sb content in the Se78 – xTe20Sn2Sbx (x = 0, 2, 4 and 6) glassy alloys. © 2018, Pleiades Publishing, Ltd.PublicationArticle Investigations of crystallization kinetics of Se 82-x Te 18 Sb x (x =0, 4, 8, 12) glassy alloys by iso-conversional approach(Taylor and Francis Ltd., 2019) Vandita Rao; N. Mehta; D.K. DwivediAt different heating rates, the crystallization temperature (T c ) are obtained from the non-isothermal differential scanning calorimetry (DSC) measurements of bulk Se 82–x Te 18 Sb x (x = 0, 4, 8 and 12) chalcogenide glasses prepared by melt quench technique. It was observed that the crystallization temperatures increase with increasing heating rates and also by increasing Sb concentration in Se–Te system. The activation energy of crystallization (E c ), the Avrami exponent (n) and rate of crystallization (K p ) have been determined from the different models. Glassy nature of as prepared samples has been confirmed using DSC techniques. © 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group.