Effect of hydrostatic pressure on the superconductivity in fluorinated Hg$_{0.8}$Ba$_2$Ca$_2$Cu$_{3.2}$O$_{8+\delta}$

The effect of hydrostatic pressure on the superconducting transition temperature was measured for the Hg-1223 phase of a fluorinated mercury cuprate high-temperature superconductor with $T_c(optim)=38\,$K. The value of the $T_c$ derivative with respect to pressure was found to be rather high ($11.0\,$K/GPa); at $P=1.5\,$GPa, $T_c=153.5\,$K. The results obtained are discussed in connection with works on the synthesis of such samples.