RF magnetron sputtering induced the perpendicular magnetic anisotropy modification in Pt/Co based multilayers* *Project supported by the National Key R&D Program of China (Grant No. 2017YFB0405700), the National Natural Science Foundation of China (Grant Nos. 11474272 and 61774144), Beijing Natural Science Foundation Key Program, China (Grant No. Z190007), and the Chinese Academy of Sciences (Grant Nos. QYZDY-SSW-JSC020, XDB44000000, and XDB28000000).

Abstract

We demonstrate that radio frequency (RF) magnetron sputtering technique can modify the perpendicular magnetic anisotropy (PMA) of Pt/Co/normal metal (NM) thin films. Influence of ion irradiation during RF magnetron sputtering should not be neglected and it can weaken PMA of the deposited magnetic films. The magnitude of this influence can be controlled by tuning RF magnetron sputtering deposition conditions and the upper NM layer thickness. According to the stopping and range of ions in matter (SRIM) simulation results, defects such as displacement atoms and vacancies in the deposited film will increase after the RF magnetron sputtering, which can account for the weakness of PMA. The amplitude changes of the Hall resistance and the threshold current intensity of spin orbit torque (SOT) induced magnetization switching also can be modified. Our study could be useful for controlling magnetic properties of PMA films and designing new type of SOT-based spintronic devices.