Stress and Grain Structure of Magnetic Thin Films Related to the Perpendicular Anisotropy

Abstract

Magnetic anisotropy of 83% Ni–Fe alloy films evaporated at oblique incidence has been observed by means of ferromagnetic resonance as a function of the substrate temperature during deposition. The observed anisotropy field Hk of the oblique incidence anisotropy is 1–1.6×103 Oe and the easy direction coincides with the incidence angle of metal vapor when the film is deposited on the substrates kept at near room temperature. But, in the film deposited at substrate temperatures higher than 150°C, the observed Hk is 3×102 Oe or less and the easy axis is directed nearly to the normal of the film plane in spite of the oblique incidence films. From these results it is concluded that the columnar structure which causes the anisotropy grows well in the films deposited on substrates kept near room temperatures, while it does not grow in the films deposited at temperatures higher than 150°C. The results of magnetization measurements also support the conclusion.