Low-temperature heat capacity and resistivity of CePd3+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 CePd_3+x shows the usual behaviour of intermediate valence compounds for Ce concentrations near or above stoichiometry.