ON THE EDGE OF TETRAVALENT CE IN CEPD7

Data on the magnetic susceptibility, low-temperature specific heat and x-ray absorption spectroscopy (Ce L(III) and M(IV,V) edges) for CePd7 and its reference compound YPd7 are presented. The respective Pauli susceptibilities chi0 of 0.11 x 10(-3) emu mol-1 and 0.50 x 10(-3) emu mol-1 and the respective Sommerfeld coefficients gamma of 9.8 mJ K-2 mol-1 and 35.8 mJ K-2 mol-1 are much smaller (per atom) than those of the corresponding components (Ce, Y and Pd). The valence extracted from the Ce L(III) edge is 3.5. The chi0/gamma-ratios are found to be 0.012 emu K2 J-1 and 0.014 emu K2 J-1 for CePd7 and YPd7, respectively. Such a value for CePd7 corresponds to that of a free-electron system instead of an intermediate-valence system (0.035 emu K2 j-1).