Investigation of a Spin Transition in a LaCoO3 Single Crystal by the Method of X-Ray Magnetic Circular Dichroism at the Cobalt K- and L2,3-Edges

Spin transitions of cobalt ions in LaCoO 3 single crystals have been studied by the method of X-ray magnetic circular dichroism (XMCD) at the K - and L 2,3 -edges of Co 3+ ions. The orbital momentum of cobalt ions obtained for the K -edge at the 3 d 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 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.