Properties of the pressure-induced superconducting state in trihydrides ScH3 and LaH3

Abstract

The present paper discusses the thermodynamic properties of the superconducting state which gets induced in the following compounds due to the influence of the high pressure: ScH3 ( p = 18 GPa) and LaH3 (p = 11 GPa). Using the Eliashberg formalism, for the Coulomb pseudopotential equal to 0.1, the following quantities have been determined: the maximum critical temperature ( K and K), the energy gap at the Fermi surface (G), the free energy (F), the thermodynamic critical field (HC), and the specific heat (both for the superconducting (CS) and the normal (CN) state). Then, the dimensionless parameters, namely, , , and , have been obtained. Those ratios deviate from the predictions of the BCS theory in the case of the studied compounds: , , , , , and . In the last step, it has been proven that the ratio of the electron effective mass () to the electron band mass (me) takes relatively high values, which are weakly dependent on the temperature. For example, it has been shown that and for .