COPTCR COMPOSITE MAGNETIC THIN-FILMS

CoPtCr composite thin films were produced by co-sputtering non-magnetic compounds such as SiO2, SiN, ZrO2, and SiC. These films were prepared without using any underlayer. It was found that the magnetic properties of CoPtCr alloys, such as the in-plane coercivity Hc and coercivity squareness S*, were significantly improved by admixing non-magnetic compounds. We obtained CoPtCr + SiO2 (10 vol%) composite films showing a high coercivity of more than 2 kOe for a thickness of 25 nm, without using an underlayer. Torque magnetometer and x-ray pole figure measurements revealed that when SiO2 is admixed, the c-axis of CoPtCr films tends to decline toward the in-plane direction, as a result of the increase of the in-plane anisotropy. From the experimental results of magnetic recording, it was found that the media noise of CoPtCr films was reduced by admixing SiO2.