X-Ray Resonance Exchange Scattering at the Nd L_2,3-Edges in Nd₂Fe₁₄B

Abstract

X-ray resonance exchange scattering has been measured at the Nd L_2,3 absorption edges on the (440) Bragg reflection in a ferromagnetic Nd₂Fe₁₄B single crystal. The magnetic spectrum at the L₂-edge reflects the spin polarization of unoccupied 5d-bands of Nd due to electric dipole transitions. The magnetic spectrum at the L₃-edge shows a more complicated structure than that at the L₂-edge. The difference in magnetic spectra between the L₂- and L₃-edges is discussed from the viewpoints of LS coupling in 5d-bands and the contributions of electric quadrupole transitions to the highly localized and partially vacant 4f-states.