Improvement of magnetic and R/W properties in longitudinal media by using CrX/Cr dual underlayer

The effect of in-plane lattice matching on the magnetic and read/write properties has been quantitatively studied in CoCr/sub 24/Pt/sub 12/B/sub 4/ or CoCr/sub 20/Pt/sub 8/Ta/sub 4/ media grown on Cr, CrMo/sub 20/ and CrMo/sub 20//Cr underlayer. It is found that by using CrMo/sub 20/ (5 nm)/Cr (5 nm) dual underlayer, significant improvement of magnetic and R/W properties are realized. It is clarified that: (1) the utilization of CrMo/Cr dual underlayer increases H/sub c/ mainly due to the improvement of in-plane crystallographic orientation; (2) the lattice misfit has a small effect on the improvement of in-plane crystallographic orientation. The improvement of in-plane crystallographic orientation by using CrX/Cr dual underlayer is suggested to be due to lattice strain at the interface of Cr and CrX underlayer, which enhances the grain growth of the magnetic layer.