LOW-TEMPERATURE SPECIFIC-HEAT AND MAGNETIC-SUSCEPTIBILITY NEAR THE PRESSURE-INDUCED QUANTUM PHASE-TRANSITION IN CE7NI3

The pressure-induced magnetic-nonmagnetic transition in a stoichiometr ic compound Ce7Ni3 was investigated using measurements of the specific heat C and the magnetic susceptibility chi on single crystals down to 0.07 K. The results show that the Neel temperature T-N decreases Line arly with increasing pressure, and vanishes at P-c=0.39 GPa. At 0.36 G Pa <P-c, the C-m/T curve deviates strongly from -lnT dependence below 0.5 K, and exhibits a broad maximum around 0.15 K. At 0.43 GPa >P-c, w hile, on the other hand, a T-independent behavior appears below 0.2 K. These findings indicate that the -lnT dependence observed near P-c be tween 0.5 and 6 K is a crossover phenomenon to a Fermi-liquid ground s tate. However, the continuous increase of chi down to 0.09 K at 0.43 G Pa is at variance with conventional Fermi-liquid theory. [S0163-1829(9 8)04542-1].