Magnetism of filled skutterudites under high magnetic fields

We measured the high-field magnetization M for skutterudite compounds of a paramagnet PrFe4Sb12 and a ferromagnet SmOs4Sb12 to investigate the characteristic magnetic properties. In PrFe4Sb12, we observed a peak structure in the dM/dH curve, which might be a level crossing effect between the singlet ground state and the excited state with a splitting energy of about 20K in the crystalline electric field (CEF) scheme. In SmOs4Sb12, the anisotropy of magnetization for H parallel to 1 0 0 parallel to and [1 1 0] was not observed, which is inconsistent with the quartet ground state in the CEF scheme. (c) 2006 Published by Elsevier B.V.