Influence of incident angle of sputtered atom on the size and shape of granule in granular films using CoFeAlSi alloy

Abstract

Granular films were prepared using Co2FeAl0.5Si0.5 alloy in two different target-substrate configurations in order to investigate the influence of the incident angle of the sputtered atoms on the granule size and the tunnel magnetoresistance (MR) effect. The samples prepared with the incident angle perpendicular to the substrates showed typical tunnel-type MR loops reflecting the superparamagnetic behavior of granules. On the other hand, in the samples prepared with glancing angle incidence, the MR loops measured by applying the magnetic field parallel to the film plane tended to saturate at relatively low fields compared to the case wherein the applied magnetic field was perpendicular to the film plane. These results indicate that the granules deposited by the glancing incident angle of the sputtered atoms have large diameter and exhibit an oblate spheroidlike shape.