GENERAL-MODEL OF PRESSURE-INDUCED TRANSITION-TEMPERATURE INCREASE WITH FOCUS ON THE HG-BA-CA-CU-O SYSTEM

A general calculation of high-pressure-induced transition temperature (T(c)) increases for oxide superconductors gives a good description fo r the Hg-Ba-Ca-Cu-0 system. Predictions are made of the maximum T(cP)t h almost-equal-to 163, 154, and 111 K compared with T(cP)exp = 164, 15 4, and 118 K respectively for the superconducting phases of Hg-1223, H g-1212, and Hg-1201 as a function of their compressibilities, agreeing with experiment. The theoretical result is in the form of a universal scaling equation for the fractional change in T(c) as a function of p ressure, which is derived from a recent phenomenological theory of sho rt coherence length superconductivity.