Spin-glass behavior in a binary Pr3Ir intermetallic compound

Polycrystalline Pr3Ir was synthesized by arc melting. Its cementite-type crystal structure (Pnma) was confirmed by powder X-ray diffraction and estimated lattice parameters are in agreement with literature. Physical properties were measured by means of the ac and dc magnetic susceptibility, electrical resistivity and heat capacity. Our results indicate spin-glass behavior in Pr3Ir with a freezing temperature Tf = 6.58 K and activation energy Ea = 2.17 kBTf. Above Tf, the dc magnetic susceptibility of Pr3Ir follows a modified Curie-Weiss dependence with a paramagnetic Curie temperature θP = 3.4 K and an effective magnetic moment μeff = 3.72 (1) μB/Pr that is somewhat larger than expected for Pr+3 (μeff = 3.5 μB/Pr). Resistivity measurement shows that Pr3Ir is a poor metal with a residual resistivity ratio about 1.6. The spin-glass scenario in Pr3Ir likely originates from the dynamic fluctuations of the magnetic interactions, as it was proposed for stoichiometric, well ordered PrAu2Si2 Pr-based ternary compound.