C-13 NMR AND STATIC MAGNETIC-SUSCEPTIBILITY IN C-60 SUPERCONDUCTORS -POSSIBLE INFLUENCE OF KONDO IMPURITY

The static spin susceptibility, chi(s)(SQ) and chi(s)(NMR), in C-60 su perconductors K3C60 and Rb3C60 was studied using a de superconducting quantum interference device magnetometer and C-13 NMR. We found that c hi(s)(SQ) has a peculiar temperature (T) dependence behaving as (1 - C T2) with a positive constant C similar to(1 x 10(-6)) deg(-2) contrary to the almost T independent chi(s)(NMR). These observations indicate a possibility that there exist Kondo-like impurities, whose Kondo temp erature is similar to 500 K and whose content is similar to 0.001 spin s per carbon. On the basis of these studies, the lattice constant depe ndence of the intrinsic spin susceptibility was established to be d ch i(s)/da(0) =(5.7+/-0.4) x 10(-4) emu/mol C-60/Angstrom in A(3)C(60) su perconductors where A is an alkali metal. [S0163-1829(98)02241-3].