Pressure Effect on the Magnetic Susceptibility of the YbInCu4 and GdInCu4 Compounds

Abstract

Pressure effect on the magnetic susceptibility of YbInCu4 and GdInCu4 compounds has been studied at fixed temperatures of 78, 150 and 300 K under helium gas pressure up to 2 kbar. The data for the YbInCu4 compound at T ≥ 100 K are well described in terms of the characteristic Kondo temperature change dT k/dlnV= — 640 K, which is typical for other Kondo systems and far exceeds the corresponding derivative values for usual mechanisms of the indirect f — f interaction. Moreover, the last contribution reveals a negligible pressure dependence for the reference GdInCu4 compound. For the YbInCu4 compound at T = 78 K, the pressure effect is significantly enhanced and is explained, in line with the temperature dependence of the susceptibility itself near the transition temperature T v, in terms of spatial dispersion of its pressure dependence due to some atomic disorder.