Magnetic circular x-ray dichroism study of La1-xSrxCoO3

The ferromagnetic oxide La1-xSrxCoO3 has been studied by magnetic circular x-ray dichroism (MCXD) in core-level absorption. In the Co 2p(3/2,1/2) abso rption, the orbital and spin magnetic moments of the Co 3d are deduced with the use of magneto-optical sum rules and compared with magnetization measu rements. In the O is absorption, large negative MCXD structures are observe d, showing that the O 2p orbitals are heavily mixed with the Co 3d orbitals and that the orbital magnetic moment of O 2p is parallel to the orbital ma gnetic moment of Co 3d and the total magnetic moment. The relative magnitud es of the spin and orbital magnetic moments are most consistently interpret ed based on the intermediate-spin states of Co 3d within the ionic model, a lthough the absolute values of the spin and orbital magnetic moments are fo und to be smaller, probably indicating that the itinerant electron descript ion of the Co 3d states is more appropriate in La1-xSrxCoO3.