ENHANCEMENT OF SUPERCONDUCTING TRANSITION-TEMPERATURE IN CECU2GE2 UNDER HIGH-PRESSURES

Enhancement of superconducting transition temperature T-c is confirmed at around 16 GPa in the pressure-induced superconductor CeCu2Ge2. The superconducting H-c-T-c phase diagrams at the low-T-c and high-T-c pr essure regions indicates that the heavy quasi particles form the singl et Cooper pairs. At both low-T-c and high-T-c pressure regions, Fermi liquid behavior of rho similar to AT(2) is observed only at low temper atures below 1 K in the normal state induced by the external field abo ve H-c2. At 21 GPa where the superconductivity disappears down to 50 m K, the temperature region following rho similar to AT(2) increases dra stically up to 40 K and the coefficient. A decreases rapidly. These re sults indicate that the strongly correlated electrons are responsible essentially for the appearance of superconductivity in this system.