UNUSUALLY LARGE T-C ENHANCEMENT IN SUPERCONDUCTING PRBA2CU3OX UNDER PRESSURE

Pressure effects on T-c of superconducting PrBa2Cu3Ox were investigate d by electrical-resistance measurements under hydrostatic pressure up to 10 GPa, using single crystals with different oxygen contents. Large positive-pressure coefficients of T-c, dT(c)/dP, with a maximum of +7 .4 K/GPa, have been observed. The zero-resistance T-c was enhanced to 105 K at a pressure of 9.3 GPa, and still keeps positive value of dT(c )/dP. The maximum T-c increase was as large as 50 K. The unusually lar ge T-c enhancement far exceeds that observed for the isostructural YBa 2Cu3Ox compounds, while x-ray diffraction under high pressure indicate s that the compressibility of PrBa2Cu3Ox is about 6.9x10(-3) GPa(-1), a value comparable to that of YBa2Cu3Ox. [S0163-1829(48)50326-8].