Specific Heat of (U/Sub 0.97/Th/sub 0.03/)Be sub 13 under Pressure

摘要

The specific heat, C, of (U/sub 0.97/Th/sub 0.03/)Be sub 13 has been measured for 0.1 less than or equal to T less than or equal to 1K and 1.6 less than or equal to P less than or equal to 7.7 kbar, and for 0.1 less than or equal to T less than or equal to 20K with P = 0. For T > 8K both the pure and Th substituted samples have essentially the same C. The peaks in C/T at 0.33 and 0.54 for P = 0 are suppressed and shifted to lower T by pressure. Anomalies in C/T can be correlated to corresponding rapid changes in magnetic susceptibility, chi. Rapid suppression of the peaks and shift of T/sub c/ to lower values is in marked contrast to the behavior found for pure UBe sub 13 whose single peak amplitude decreases approximately linearly with P to about 60% at 9.3 kbar. The broad ''shoulder'' in C/T near 2K that is found for UBe sub 13 , but not for any other heavy-fermion compound, HFC, is completely suppressed in the Th substituted sample. (ERA citation 12:037228)