Sm-based Filled Skutterudite Phosphides SmT4P12SmT4P12 (T=FeT=Fe, Ru, Os) Studied by 3131P-NMR and μμSR

The Sm-based filled skutterudite phosphides SmT4P12SmT4P12 (T=FeT=Fe, Ru, Os) have been studied by 3131P-NMR (nuclear magnetic resonance) and μμSR (muon spin relaxation). The ferromagnetic order and the heavy fermion behavior in SmFe4P12SmFe4P12 and the antiferromagnetic order in SmOs4P12SmOs4P12 were confirmed by 3131P-NMR and μμSR. In SmRu4P12SmRu4P12, a successive anomaly around the metal–insulator transition temperature and around the Néel temperature was observed by 3131P-NMR in high applied magnetic fields. The μμSR results of SmRu4P12SmRu4P12 indicate the magnetic order below the metal-insulator transition temperature, which supports the existence of the octupolar order in SmRu4P12SmRu4P12.