Electronic structure, photoemission, and magnetism inGd2Co andEr2Co glasses

The electronic and magnetic structures of amorphous ${\mathrm{Gd}}_2$Co and ${\mathrm{Er}}_2$Co are studied by ultraviolet and x-ray photoemission measurements and band calculations. The spectra for both glasses show a band of Co 3d levels centered at a binding energy $E_B$ of about -1.0 eV and peaks arising from 4f levels at $E_B$=-8.4 eV and $E_B$apeq2-5–9 eV for Gd and Er, respectively. Magnetization data have shown that a-${\mathrm{Gd}}_2$Co possesses a ferrimagnetic structure with a small Co moment. The linear-muffin-tin-orbital method is used to perform self-consistent, spin-polarized calculations in the semirelativistic approximation for ${\mathrm{Gd}}_2$Co. Because of the complexity of the glassy structure, the calculations are performed for body-centered-tetragonal and cubic fluorite structures, and the sensitivity to local environment effects studied. The calculations are in a good overall agreement with the photoemission and magnetic-moment results.