Recording performance of CoCrPt-(Ta, B)/TiCr perpendicular recording media

The magnetic properties, microstructure and the recording performances of C oCrPt-(Ta, B)/TiCr perpendicular magnetic recording media were studied in c onjunction with the effect of thermal agitation. The addition of Th or B to CoCrPt media significantly improves its low noise performance, mainly due to the reduction of grain size and intergranular magnetic interactions. How ever, adding Ta or B also reduces the value of perpendicular magnetic aniso tropy, K-u, especially in the initial growth layer, resulting in the degrad ation of thermal stability. In order to achieve high thermal stability with out degrading the low noise performance of these media, an M-r/M-s value of nearly 1.0 is required. This may be achieved by suppressing of the reducti on of K-u and the reducing intergranular magnetic interactions, whilst main taining their small grain size.