TDPAC study of 140Ce local susceptibility in the Kondo insulator system CeNi 1 − xCo xSn

Abstract

We have measured the local magnetic susceptibility ( χ loc) of 140Ce in the alloy system CeNi 1 − x Co x Sn for x = 0, 0.3 and 0.38 in the range 28–300 K using TDPAC method. The results show strongly reduced χ loc values in all the alloys. Using the Coqblin-Schrieffer model we obtain the Kondo temperatures T K to be 90, 112 and 170 K for x = 0.0, 0.38 and 0.30, respectively. In addition, for x = 0.38, the data show an abrupt drop in the χ loc value at 48 K indicating a first-order valence transition for Ce ions.