A STUDY OF THE THERMODYNAMIC SUPERCONDUCTING STATE PARAMETERS IN SELENIUM UNDER HIGH PRESSURE.

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 (m"e/me) in the entire range of the superconducting state existence takes a high value and its maximum equals 1:505 for T = TC. Furthermore, it has been shown that the dimensionless ratio: 2Δ (0) /kBTC deviates from the predictions of the conventional BCS theory. [ABSTRACT FROM AUTHOR]