PERPENDICULAR MAGNETIC ANISOTROPY OF Fe-Ti ALLOY SPUTTERED FILMS

Abstract

About 7000 A thick Fe1-xTix ( 0≤X<30 at.% ) films have been prepared by Facing Targets Sputtering method under various sputtering conditions such as Ar gas pressure PAr of 0.8∼7 mTorr, bias voltage to substrate VB of 0-150 V and substrate temperature Ts of 25400 °C. The saturation magnetization Ms vanished to zero at Ti content CTi from 19 to 23 at.% where the film structure became amorphous, depending on the sputtering conditions. The films deposited at PAr of 7 mTorr and at VB of -90 and -150 V exhibited perpendicular anisotropy field Hk as high as 23 kOe, which was estimated from the in-plane magnetization loop, just before the Ms became nearly zero. On the other hand, At Ts of 300 °C, the films with CTi of 1820 at.% showed Hk as high as 3 kOe and Ms as relatively large as 600 emu/cc. These films may be useful as a perpendicular magnetic recording medium because they have also high perpendicular coercivity as high as 900 Oe.