LOW-TEMPERATURE MAGNETIC-BEHAVIOR IN CEPTGA3

A low temperature study of CePtGa3 shows a peak in the heat capacity of ∼2.8 J/mol Ce K at 1.7 K, which is shifted to higher temperatures (∼6 K at 9.8 T) in magnetic fields. Furthermore, the heat capacity data are consistent with spin-glass-like behavior. The 8 T field data below 0.2 K suggests a γ of ∼120 mJ/mol Ce K2. AC magnetic susceptibility data as a function of the magnetic field (up to 2 T) suggests some small fraction of the Ce spins are involved with percolating antiferromagnetic clusters. Unlike the ordinary spin glasses, the Ce3+ ions in CePtGa3 occupy periodic lattice sites. The random RKKY interactions between spins which provides the basis for spin-glass-like behavior is induced by the random distribution of Pt and Ga atoms around the Ce3+ ions. © 1990.