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.

中文翻译：

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超导体的热稳定性

制定了超导阶段的稳定性判据。由此证实了先前为持续电流建立的前提条件的有效性。给出了临界温度T _c附近的比热和超导电子浓度的温度依赖性。分析了由电子-声子相互作用和超精细耦合介导的同位素效应。提出了一些旨在验证该分析的实验，其中包括一个获得高T _c化合物比热的实验。