Soft-x-rayM2,3absorption spectra of some transition-metal halides

Abstract

The soft-x-ray ${M}_{2,3}$ absorption spectra due to excitation of $3p$ electrons of transition metals, Cr, Mn, Fe, Co, and Ni, and the metal ions in the halides, Cr${\mathrm{Cl}}_{2}$, Cr${\mathrm{Br}}_{3}$, Mn${\mathrm{F}}_{2}$, Mn${\mathrm{Cl}}_{2}$, Mn${\mathrm{Br}}_{2}$, Fe${\mathrm{Cl}}_{2}$, Fe${\mathrm{Br}}_{2}$, Co${\mathrm{F}}_{2}$, Co${\mathrm{Cl}}_{2}$, Co${\mathrm{Br}}_{2}$, Ni${\mathrm{Cl}}_{2}$, and Ni${\mathrm{Br}}_{2}$, are obtained at room temperature. Synchrotron orbital radiation from a 1.3-GeV electron synchrotron at the Institute for Nuclear Study in Tokyo is used as a light source. The fine structures of the spectra are observed on the low-energy side of the absorption threshold of all the transition-metal halides except for nickel halides. These structures suggest the existence of the localized $d$ levels which lie a few eV below a $4s$ band.