Effect of Pt on the Intergranular Exchange Coupling in CoCrTaPt Thin Film Media Prepared under Ultra Clean Sputtering Process

抄録

The effect of Pt addition on magnetic properties for CoCrTaPt media with extremely thin Cr underlayer of 2.5 nm fabricated under ultra clean sputtering process are connected with the magnetic anisotropy field of grains, the microsturucture, and intergranular magnetic coupling. As a results, (1)Pt addition more than 8 at% decreases the magnetrocrystalline anisotropy field of the grains. (2)Pt addition more than 8 at% disturbs a formation of Cr segregated rain boundary structure, inducing intergranular exchange coupling. (3) The upper limit of Pt addition is proposed to be 5-6 at%.