Thermal Stability of Superconductors

TL;DR

This paper develops a stability criterion for superconductors, analyzes temperature effects on their properties, and presents experiments to validate the theoretical predictions, including studies on high-$T_c$ materials.

Contribution

It introduces a new stability criterion for superconductors and provides experimental validation, including specific heat measurements of high-$T_c$ compounds.

Findings

Confirmed the validity of a stability prerequisite for persistent currents.

Provided temperature dependence data for specific heat and electron concentration near $T_c$.

Presented experimental results on the isotope effect and specific heat in high-$T_c$ superconductors.

Abstract

A stability criterion is worked out for the superconducting phase. The validity of a prerequisite, established previously for persistent currents, is thereby confirmed. Temperature dependence is given for the specific heat and concentration of superconducting electrons in the vicinity of the critical temperature $T_c$. The isotope effect, mediated by electron-phonon interaction and hyperfine coupling, is analyzed. Several experiments, intended at validating this analysis, are presented, including one giving access to the specific heat of high-$T_c$ compounds.