Magnetic Anisotropy and Columnar Structure of Fe Films Made by Simultaneous Evaporation with Oblique Incidence from Two Sources

Fe film samples were prepared by oblique simultaneous evaporation from two sources with an angle Ø between the two planes of incidence, the magnetic anisotropy in the film plane was measured, and the columnar structure was observed by SEM. For samples prepared with Ø≤45°, the easy axis of anisotropy and columnar grain alignment are in the direction perpendicular to the plane bisecting the two planes of incidence; for samples with Ø≥45°, they are parallel to the bisecting plane. A mechanism of anisotropic arrangement of the columnar grains based on a self-shadowing effect is proposed. The magnetic anisotropy calculated from the columnar structure assuming such a mechanism was in fairly good agreement with the measured anisotropy.