Thermodynamics of the hydrogen dominant potassium hydride superconductor at high pressure

D. Szczȩśniak; R. Szczȩśniak

doi:10.1016/j.ssc.2015.03.015

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arXiv · 1502.03017

Thermodynamics of the hydrogen dominant potassium hydride superconductor at high pressure

D. Szczȩśniak·R. Szczȩśniak

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Abstract

In the present paper we report comprehensive analysis of the thermodynamic properties of novel hydrogen dominant potassium hydride superconductor (KH$_{6}$). Our computations are conducted within the Eliashberg theory which yields quantitative estimations of the most important thermodynamic properties of superconducting phase. In particular, we observe, that together with the increasing pressure all the thermodynamic properties decrease, e.g. $T_{C} \in \left< 72.91 , 55.50 \right>$ K for $p \in \left< 166 , 300 \right>$ GPa. It is predicted that such decreasing behavior corresponds to the decreasing hydrogen lattice molecularization with increasing pressure value. Futhermore, by calculating the dimensionless thermodynamic ratios, familiar in the Bardeen-Cooper-Schrieffer theory (BCS), it is proved that KH$_{6}$ material is a strong-coupling superconductor and cannot be quantitatively described within the BCS theory.

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D. Szczȩśniak, R. Szczȩśniak. 2015-02-10. Thermodynamics of the hydrogen dominant potassium hydride superconductor at high pressure. https://doi.org/10.1016/j.ssc.2015.03.015

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