Perpendicular magnetic anisotropy on sputtered FeTi films

Abstract

Magnetic properties and crystalline structures for sputtered FeTi films (0-40 at% Ti in composition), have been examined. The film structures were divided into three regions, bcc phase, transition region from bee to amorphous phase, and amorphous phase. In the transition region (15-18 at% Ti) from bcc to amorphous phase, FeTi films with perpendicular magnetic anisotropy were found. Saturation magnetization, magnetic anisotropy field, and perpendicular coercivity for a typical FeTi film (16.8 at% Ti) prepared in the transition region were 300 emu/cc, 2.7 kOe, and 710 Oe, respectively. Crystalline microstructures for FeTi films with perpendicular magnetic anisotropy are composed of amorphous phase and isolated pillar or pin-like crystalline grains (200-500 A) with bcc phase surrounded by the amorphous phase. Therefore, the origin of perpendicular magnetic anisotropy on FeTi films is mainly attributed to the grains shape anisotropy.