We report on the results of x-ray fluorescence measurements of ${\mathrm{CrO}}_2$ thin film, which show half-metallic electronic structure. The experimental finding that the elastically scattered radiation observed in Cr $L_{2,3}$ x-ray emission spectra is more prominent in ${\mathrm{CrO}}_2$ than in metallic Cr is considered evidence for the half-metallic character of ${\mathrm{CrO}}_2.$ The presence of an intense elastic peak in resonantly excited ${\mathrm{CrO}}_2$ spectra is due to the long lifetime of the excited states and suppression of the relaxation channel because of the unusual almost currentless character of minority spin states.

• Received 22 August 2002

DOI:https://doi.org/10.1103/PhysRevB.67.155105