Ashok Kumar

Dr. Ashok Kumar

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Research Focus & Metrics

Academic Career Length

36Years (1991-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 January 2022 in Journal of Materials Science: Materials in Electronics
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AVAmit Kumar Vats
Amit Kumar Vats
AKAshok Kumar
Ashok Kumar
PRParasmani Rajput
Parasmani Rajput
AKAshavani Kumar
Ashavani Kumar

7 December 2019 in Applied Physics A
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JSJashandeep Singh
Jashandeep Singh
AKAmit Kumar
Amit Kumar
UGUttam Kumar Goutam
Uttam Kumar Goutam
AKAshok Kumar
Ashok Kumar

22 January 2015 in RSC Advances
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AKAstakala Anil Kumar
Astakala Anil Kumar
AKAshok Kumar
Ashok Kumar
JQJ. K. Quamara
J. K. Quamara
GDG R Dillip
G R Dillip
SJSang Woo Joo
Sang Woo Joo
JKJitendra Kumar
Jitendra Kumar
In this paper, we report the synthesis of Fe containing strontium stannate (SrSnO3) nanoparticles by a facile cost-effective wet chemistry route using cetyltrimethyl ammonium bromide (CTAB) as a surfactant. Thermogravimetric analysis together with differential scanning calorimetric data revealed the formation of SrSn(OH)6 as the initial compound, which led to the formation of SrSnO3 via three main endothermic dehydration cycles. The X-ray diffraction patterns of the final compound revealed the formation of the orthorhombic phase of SrSnO3 with Pbnm symmetry, and exhibited the contraction of cell volume with increase in Fe content. Raman spectra showed peaks at 220, 256, 306, 404, 452 and 561 cm−1, which corresponds to Sn–O and O–Sn–O band stretching. The band gap values were found to be 4.17, 3.81 and 3.52 eV for the samples with 0, 2 and 4 at% Fe content, respectively. The photoluminescence spectra also confirmed the red shift of band emission peak observed around 370 nm. The relative permittivity was observed to be low and showed steady variation with temperature and Fe content. The dielectric relaxation time was found to decrease with temperature and increase with Fe content. The ac conductivity values were 3.23 × 10−8, 3.98 × 10−8 and 4.47 × 10−8 Ω−1 cm−1, and activation energy was found to be 0.22, 0.34 and 0.44 eV for pristine and Fe (2 and 4 at%). Conductivity analysis suggested the hopping of charge carriers in the crystal, as the possible mechanism for electric conduction.

13 July 2020 in International Journal of Minerals, Metallurgy and Materials
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JSJashandeep Singh
Jashandeep Singh
AKAshok Kumar
Ashok Kumar

14 June 2020 in Ionics
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JSJashandeep Singh
Jashandeep Singh
IRIrina Rogge
Irina Rogge
UGUttam Kumar Goutam
Uttam Kumar Goutam
AKAshok Kumar
Ashok Kumar