Ti/sub x/Zr/sub 1-x/ underlayers for CoCrPtB perpendicular magnetic recording media

We describe the effects of Ti/sub x/Zr/sub 1-x/ underlayers on the microstructural and magnetic properties of CoCrPtB layers. We found that as the Zr atomic composition increases in the Ti/sub x/Zr/sub 1-x/ underlayers, the unit cells of the Ti/sub x/Zr/sub 1-x/ underlayers expand. The Ti/sub x/Zr/sub 1-x/ (0002) texture is strongest as the Zr atomic composition ranges from 40% to 60%. In addition, the CoCrPtB (0002) texture induced by the (0002) textured Ti/sub x/Zr/sub 1-x/ underlayer is enhanced at these optimizing Zr compositions. The grain size of the CoCrPtB layers deposited onto the Ti/sub x/Zr/sub 1-x/, underlayers is around 7.5-9.5 nm. Stacking fault streaks observed by transmission electron microscopy indicate that stacking faults exist in the CoCrPtB films with the Ti/sub x/Zr/sub 1-x/ underlayers. The Hc (coercivity) and S* (squareness) of the CoCrPtB magnetic layers deposited onto the pure Ti and Zr underlayer were higher than those with the TiZr alloy underlayers.