North-Holland, Amsterdam PRESSURE DEPENDENCE OF THE T, OF Bi-Ca-Sr-Cu-0 UP TO 80 KBAR

The superconducting transition temperature T, of polycrystalline Bi-Ca-Sr-Cu-0 ( T, = 92.4 K) was measured by monitoring the electrical resistivity in a diamond anvil cell. T, is found to decrease at a rate of dT,/dp =-0.16 K/kbar up to 80 kbar. This is the first high temperature superconductor which shows a clear decrease of T, with pressure. The pressure dependence is qualita-tively explained in terms of a Hubbard-like model. 1