Ti grain cutting layer and Pt underlayer for CoCr based single magnetic layered perpendicular magnetic recording media

Summary form only given. For CoCr based perpendicular magnetic recording (PMR) disks, a Ti underlayer has been commonly used because it is known to improve the c-axis preferred orientation of the recording media. However, it has also been reported that a magnetically unstable initial layer exists between the Ti underlayer and the CoCr based recording layer because of large lattice mismatch between Ti and the recording layer. In this work, we propose a new underlayer structure composed of Ti/Pt double layers for a CoCrPtX magnetic film, which was found to successfully reduce the grain/domain size and exchange coupling in the recording layer, maintaining excellent c-axis preferred orientation of the film.