Preparation of High-Coercivity Co–Pt Alloy Films by Target-Facing Type of High-Rate Sputtering

Abstract

Co 1- x Pt x (0≦ x ≦0.2) thin films were prepared by using a Target-Facing type of high-rate sputtering (TFTS). The films deposited at lower argon gas pressure P Ar (≦5 mTorr) have only a low coercive force H c (<700 Oe). However, the value of H c for films deposited at higher P Ar (≧10 mTorr) increases monotonically as the Pt content increases, and films with high H c (>1 kOe) can be obtained at a Pt content of above 11 at%. These films, whose crystallites are oriented randomly, also have a large inplane uniaxial magnetic anistropy constant K 1 (\cong2.5×10 6 erg/cc) and excellent hysteresis loop squareness ( S \cong0.87, S * \cong0.98).