Journal of Physical Studies 17(1), Article 1701 [5 pages] (2013) DOI: https://doi.org/10.30970/jps.17.1701 A STUDY OF THE THERMODYNAMIC SUPERCONDUCTING STATE PARAMETERS IN SELENIUM UNDER HIGH PRESSURE A. P. Durajski{1}, D. Szczęśniak{2,3}, R. Szczęśniak{1} {1}Institute of Physics, Częstochowa University of Technology, Al. Armii Krajowej, 19, 42-200 Częstochowa, Poland {2}Institute of Physics, Jan Długosz University in Częstochowa, Al. Armii Krajowej, 13/15, 42-200 Częstochowa, Poland, {3}Institute for Molecules and Materials UMR 6283, University of Maine, Ave. Olivier Messiaen, 72085 Le Mans, France, e-mail: adurajski@wip.pcz.pl

The thermodynamic properties of the superconducting state that induces in selenium at the pressure of 100 GPa have been described in the paper. In the framework of the Eliashberg theory values of the energy gap at the temperature of close to zero Kelvin and electron effective mass have been determined. Our study shows that the ratio of the electron effective mass to electron band mass $\left(m_{e}^{*}/m_{e}\right)$ in the entire range of the superconducting state existence takes a high value and its maximum equals $1.505$ for $T=T_{\rm C}$. Furthermore, it has been shown that the dimensionless ratio: $2Δ\left(0\right)/k_{\rm B}T_{\rm C}$ deviates from the predictions of the conventional BCS theory.

PACS number(s): 74.20.Fg, 74.25.Bt, 74.62.Fj

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