arXiv subjects

Yuri A. Timofeev

Publications and source records attributed to Yuri A. Timofeev.

2 recordsLinked to original sources

arXiv2002

New Methods for Investigating Superconductivity at Very High Pressures

We review recent advances in diamond anvil cell development, focusing on the details of magnetic susceptibility techniques. We have developed and implemented highly sensitive technique that allowed observations of superconductivity using magnetic susceptibility at megabar pressures, including the observation of a Tc in sulfur to above 230 GPa. The advancement of the technique should enable the most demanding diamond anvil cell applications. The Tc(P) data for simple s-p metals (Se,S, MgB_2) are presented and analyzed. The possibility for a phonon-assisted electronic topological transition (ETT) in MgB_2 at high pressure is discussed.

cond-mat.supr-con↗

arXiv2001

Superconductivity in the Chalcogens up to Multimegabar Pressures

Highly sensitive magnetic susceptibility techniques were used to measure the superconducting transition temperatures in S up to 231($\pm$5) GPa. S transforms to a superconductor with T$_c$ of 10 K and has a discontinuity in T_c dependence at 160 GPa corresponding to bco to beta-Po phase transition. Above this pressure T_c in S has a maximum reaching about 17.3(+/-0.5) K at 200 GPa and then slowly decreases with pressure to 15 K at 230 GPa. This trend in the pressure dependence parallels the behavior of the heavier members Se and Te. Superconductivity in Se was also observed from 15 to 25 GPa with T_c changing from 4 to 6 K and above 150 GPa with T_c of 8 K. Similiarities in the T_c dependences for S, Se, and Te, and the implications for oxygen are discussed.

cond-mat.supr-con↗