Electronic structure of crystalline FeSi and FeGe

X-Ray photoelectron valence band spectra were recorded for stoichiometric compounds FeSi and FeGe; their electronic structure was calculated by the ab initio full-potential linear muffintin orbital method. For nonmagnetic FeSi, good agreement was obtained between the calculated densities of states and the X-ray photoelectron spectrum in both peak positions and forbidden gap. For FeGe, which is an antiferromagnet, the nonmagnetic calculation yields worse agreement with experiment and explicitly indicates that the paramagnetic phase is unstable. In both compounds, the calculation gives a high degree of d—p hybridization and covalence, which is estimated quantitatively. In FeGe, the degree of covalence of the Fe-Fe bond is higher than that of the Fe-Ge bond. Translated fromZhurnal Strukturnoi Khimii, Vol. 39, No. 6, pp. 1098–1102, November–December, 1998.