Effects of Pt addition on the magnetic and crystallographic properties of Co-Cr-Pt thin-film media

The magnetic and crystallographic properties of Co-Cr-Pt/Cr films at various Pt contents have been investigated using high-resolution transmission electron microscopy (HREM). The Cr underlayers and Co85-xCr15Ptx(x=2-20 at%) films are deposited using de magnetron sputtering under high mobility deposition conditions. The Cr underlayers and Co-Cr-Pt films at any Pt content had bcc [100] and hcp [11.0] growth axes. Unlike previously reported work, no strong fee Co(lll) texture was observed. The in-plane coercivity and the magnetocrystalline anisotropy constant increased as Pt was added, and both showed a maximum value at 12 at% Pt. Also contrary to previous works, the addition of Pt increased the average grain size of the Co-Cr-Pt films from 17 nm at 2 at% Pt, to 23 nm at 12 at% Pt. This grain size change may be one reason for the coercivity increases with the addition of Pt.