Investigation of a Spin Transition in a LaCoO{sub 3} Single Crystal by the Method of X-Ray Magnetic Circular Dichroism at the Cobalt K- and L{sub 2,3}-Edges

Spin transitions of cobalt ions in LaCoO{sub 3} single crystals have been studied by the method of X-ray magnetic circular dichroism (XMCD) at the K- and L{sub 2,3}-edges of Co{sup 3+} ions. The orbital momentum of cobalt ions obtained for the K-edge at the 3d level in the region of the spin transition in the temperature range from 25 to 120 K increases by a factor of approximately 1.6, whereas the slope of the magnetization curve value in the same temperature range and magnetic field increases by a factor of more than 10. XMCD experiments at the cobalt L{sub 2,3}-edges demonstrate gradual growth of the ratio of the orbital momentum to the spin one L/S from 0.48 to 0.53 in the temperature range from 60 K to 120 K.