PRESSURE-DEPENDENCE OF T(C) IN NDBA2CU3O7-DELTA TO 6 GPA

The superconducting transition temperature T(c) for NdBa2Cu3O7-delta i s measured as a function of pressure to 6 GPa. The pressure applied to these materials is directly measured near T(c), which is determined b y monitoring the ac susceptibility as a function of temperature. It ha s been suggested that the apparent absence of superconductivity in PrB a2Cu3O7-delta is due, at least in part, to the interaction of 4f elect rons of Pr3+ with the Cu-O plane. In light of this speculation, applyi ng pressure to NdBa2Cu3O7-delta might be expected to increase the inte raction of 4f electrons of Nd3+ with electrons in the Cu-O plane and r educe T(c). Our results indicate that T(c) increases with applied pres sure.