Low-temperature heat capacity and resistivity of CePd_3+xand MPd₃(M=Lu, La, Y and Sc)

Abstract

Low-temperature heat capacity data are presented for a series of AuCu3 type MPd3 compounds (M=Ce, La, Lu, Y and Sc). The coefficient gamma of the linear term of the electronic specific heat of the non-magnetic compounds ranges from 0.28 for LaPd3 to 8.2 mJ mol-1 K-2 for ScPd3 and reflects a lower density of states at the Fermi surface than that of M or Pd. The high gamma value of intermediate valence CePd3 is confirmed and shown to vary with Ce content near stoichiometry: a maximum value of 38.6 mJ mol-1 K-2 is obtained while the electronic contribution to the T3 term of the specific heat is found to be very small. The electrical resistivity of CePd3+x shows the usual behaviour of intermediate valence compounds for Ce concentrations near or above stoichiometry.