Thermodynamic properties of the f-electron-nuclear hyperfine-coupled composite multiplets of Pr ions in filled-skutterudite PrRu4P 12

Abstract

It has recently been found that composite multiplets are formed by the hyperfine coupling between the triplet crystalline-electric-field ground state of the 4f electrons and the 141Pr nuclear spin in Pr ions of the filled skutterudite PrRu4P12. Entropy analysis of the characteristic Schottky-type peak structure appearing in the low-temperature specific heat demonstrates that it is actually caused by thermal excitations of not only 4f electrons but also 141Pr nuclei. The hyperfine coupling constant for Pr ions in nonmetallic PrRu4P12 is determined to be A +0.050(2) K, which is almost the same as in metallic Pr-based compounds. This fact corroborates that the intra-ion hyperfine coupling of Pr ions is independent of the type of material. © Published under licence by IOP Publishing Ltd.