Department of Applied Physics Research Seminar: Mohamed Oudah
Dr. Mohamed Oudah is a postdoctoral fellow at Stewart Blusson Quantum Matter Institute, University of British Columbia.
Mohamed studies superconductivity in the antiperovskite oxide Sr3SnO and Barium Copper chalcogenides.
We investigate the NaCl-type superconducting series Ag1-xSn1+xSe2 by means of XPS and Mössbauer spectroscopy. By varying the Ag/Sn ratio we observe a change in the ratio of 2+ and 4+ state of Sn as probed by XPS, with increasing 2+ state as the Sn amount is increased. In contrast, we detect only one state for Sn in the Mössbauer spectra, which corresponds to the unusual 3+ state for Ag:Sn of 1:1. We study the Mössbauer spectra at low temperature to elucidate the charge fluctuations scenario for Sn. Furthermore, we calculate the band structure of AgSnSe2, which reveal contributions from all three elements near the fermi level. We discuss the experimentally measured state of Sn in light of our calculations. We relate these findings to materials with higher entropy and briefly highlight recent projects at UBC on high-entropy oxides.
Host: Prof. Jose Lado (Department of Applied Physics)
Zoom link available on request to [email protected].
Everybody interested welcome to attend!