Resonant X-Ray Emission Spectroscopy in Dy Compounds

The excitation spectrum of the L3-M5 X-ray emission of Dy compounds in the pre-edge region of Dy L3 X-ray absorption near edge structure (L3-XANES) is theoretically investigated based upon the coherent second order optical formula with mul-tiplet coupling effects. The spectral broadening of the excitation spectrum is determined by the M5 core hole lifetime, being free from the L3 core hole lifetime. The fine pre-edge structure of the L3 edge due to the 2p→4f quadrupole transition can be seen in the excitation spectrum, while this structure is invisible in the conventional XANES, in agreement with the recent experimental results. We clarify the conditions for the excitation spectrum to be regarded as the absorption spectrum with a smaller width. The resonant X-ray emission spectra for various incident photon energies around the L3 edge are also calculated.