Observation of heavy-fermion like behaviour and anomalous magnetism in a Pr-based metal

Abstract

The results of magnetic susceptibility, electrical resistivity and heat capacity measurements on the pseudoternary solid solutions, Pr_1−xGd_xCu₂Si₂, are reported. These is an unusual enhancement of Néel temperature (T_N) of Pr sub-lattice in PrCu₂Si₂ (T_N=21K) over that of GdCu₂Si₂ (T_N=13K). Present results indicate that this anomalous magnetism gets relatively depressed by positive chemical pressure effects induced by Gd or Y substitution. Interestingly, the linear coefficient of heat capacity above T_N is found to be large for PrCu₂Si₂ (~225 mJ/mol K²) and this parameter undergoes a drastic reduction with Gd substitution. Such a strong dependence of this linear term on the positive chemical pressure indicates possible heavy fermion behaviour of Pr in a metallic environment.