Upendra Kumar

Upendra Kumar


Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

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

Representative Publications

View All Publications
26 March 2020 in Polymer Composites
Verified
Journal Article
Closed access
PDF file
KKKamal Kumar Khichar
Kamal Kumar Khichar
SDSuraj Bhan Dangi
Suraj Bhan Dangi
VDVimala Dhayal
Vimala Dhayal
UKUpendra Kumar
Upendra Kumar
SHSonia Zeba Hashmi
Sonia Zeba Hashmi
PAParvez Ali
Parvez Ali

1 September 2017 in Electrochimica Acta
Verified
Journal Article
Closed access
MMMandira Majumder
Mandira Majumder
RCRam Bilash Choudhary
Ram Bilash Choudhary
SKShankar P. Koiry
Shankar P. Koiry
ATAnukul Thakur
Anukul Thakur
UKUpendra Kumar
Upendra Kumar

1 August 2020 in Journal of Magnetism and Magnetic Materials
Verified
Journal Article
Closed access
BCB.L. Choudhary
B.L. Choudhary
UKUpendra Kumar
Upendra Kumar
SKShalendra Kumar
Shalendra Kumar
SCSubhash Chander
Subhash Chander
SKSudhish Kumar
Sudhish Kumar
PAP.A. Alvi
P.A. Alvi

4 June 2018 in Journal of Thermal Analysis and Calorimetry
Verified
Journal Article
Closed access
PDF file
UKUpendra Kumar
Upendra Kumar
DYDharmendra Yadav
Dharmendra Yadav
ATAnukul Thakur
Anukul Thakur
KSKamal K. Srivastav
Kamal K. Srivastav
SUShail Upadhyay
Shail Upadhyay

1 April 2020 in Materials Characterization
Verified
Journal Article
Closed access
UKUpendra Kumar
Upendra Kumar
KAKumar Ankur
Kumar Ankur
DYDharmendra Yadav
Dharmendra Yadav
SUShail Upadhyay
Shail Upadhyay

1 August 2019 in Journal of Advanced Ceramics
Verified
Journal Article
Open access
PDF file
DYDharmendra Yadav
Dharmendra Yadav
UKUpendra Kumar
Upendra Kumar
SUShail Upadhyay
Shail Upadhyay
Phase pure powders of SrCeO3 and Sr2CeO4 have been synthesized by calcination at 1000 °C for 14 h via solid state ceramic route. Ceramics/pellets of these samples have been obtained by sintering at 1200 ℃ for 12 h. The Rietveld refinement of X-ray diffraction (XRD) pattern of sintered powders confirmed orthorhombic structure of both the samples with space group Pnma and Pbam for SrCeO3 and Sr2CeO4, respectively. Scanning electron microscopic (SEM) studies indicated that both the compounds have dense microstructure, but morphology and size of the grains are different. The impedance spectroscopy technique has been employed to study the relaxation phenomenon. DC conductivity of the samples has been measured in the temperature range of 200–600 ℃ to understand the conduction mechanism. The activation energy for relaxation (Erelax) and DC conduction (Econd) are found to be the same for both the compounds. Based on the numerical value of activation energies, relaxation and conduction mechanism in both the samples are attributed to migration of doubly ionized oxygen vacancies (Vo••). Photoluminescence technique has been employed to confirm the existence of oxygen vacancies. These studies have indicated that migration of oxygen vacancies in Sr2CeO4 is occurring mainly along a and c direction, i.e., via perovskite cells. Further, the present work has clearly indicated that besides optical properties, electrical properties of Sr2CeO4 are also interesting and can be utilized for various applications such as oxide ion conduction electrolyte in solid oxide fuel cells (SOFCs).