One-dimensional tellurium chains: Crystal structure and thermodynamic properties of PrCuxTe2 (x ~ 0.45)

X-ray diffraction, crystal structure, magnetization, and heat capacity results are presented for the rare earth – chalcogenide ternary system PrCu0.45Te2 and its non-4f analogue LaCu0.40Te2. The crystal structure of PrCu0.45Te2 is characterized by chains of edge and corner-sharing CuTe4 tetrahedra and Pr centered in polyhedra comprised of Cu and Te. The Cu site is partially occupied and exhibits signatures of local disorder. Magnetic susceptibility measurements show a Curie-Weiss temperature dependence consistent with a Pr3+ state. No magnetic ordering is observed down to 1.8 K, but the negative Curie-Weiss temperature suggests an antiferromagnetic exchange interaction. Importantly, the low temperature heat capacity of PrCu0.45Te2 is strongly enhanced by comparison to LaCu0.40Te2, suggesting that there is a build-up of entropy that is associated with the 4f-electrons from the Pr3+ ions. These features reveal possible spin frustration behavior and introduce this family of materials as a template for studying new phenomenon.