Electronic structure, photoemission, and magnetism in Gd\u3csub\u3e2\u3c/sub\u3eCo and Er\u3csub\u3e2\u3c/sub\u3eCo glasses

The electronic and magnetic structures of amorphous Gd2Co and Er2Co 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 EB of about -1.0 eV and peaks arising from 4f levels at EB=-8.4 eV and EBapeq2-5–9 eV for Gd and Er, respectively. Magnetization data have shown that a-Gd2Co 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 Gd2Co. 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