ELECTRON-MICROSCOPY OF EVAPORATED AND SPUTTERED GD-CO AND HO-CO FILMS

Amorphous films of evaporated Gd/Co and Ho/Co and bias‐sputtered Gd/Co are investigated by electron diffraction, dark field transmission electron microscopy and, by means of Lorentz microscopy. The films are annealed in the electron microscope and structural as well as magnetic changes are observed. A model of anisotropic deactivation of Gd by oxygen diffusion along column boundaries is developed to explain the perpendicular anisotropy which is supported by the annealing experiments. The general source of the uniaxial perpendicular anisotropy is seen in anisotropic pair ordering of excess magnetic moments for the case of oxidation‐induced anisotropy and in atomic pair ordering due to different backsputtering rates in bias‐sputtered films. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA