Spin and orbital electronic states of Sm 4f electrons in (Sm, Gd)Al 2

Abstract

(Sm,Gd)Al 2 was expected to be a ferromagnet without net magnetization at a certain compensation temperature, T Comp. For this material, X-ray magnetic circular dichroism (XMCD) study on the spin and orbital moments of Sm 4f electrons has been carried out. The conventional magnetic field switching method is not suitable because the special magnetic property of this material and helicity switching method was tried. To get a quantitative estimation of the spin and orbital magnetic moments for 4f electrons in samarium ions, the correction factor for the sum rule of spin moment was obtained by a complete atomic multiplet calculation. From our study, the existence of long-range ordering of both spin and orbital magnetic moments at T Comp is verified. The spin and orbital magnetic moments of Sm 4f electrons are found to align antiparallel with each other. When the temperature is lower (higher) than T Comp, the magnitude of total spin magnetic moment, which includes the contributions from doped ions and conducting electrons, is found to be smaller (larger) than that of the orbital one.