Effects of alloying additions in the CrMo underlayer on the grain size and magnetic properties of CoCrPt longitudinal media

The alloy doping effects of the CrMo underlayer were investigated on the texture, grain size, and magnetic properties of CoCrPt longitudinal media. 5% Mn dissolving into CrMo lattices enhanced the texture of the recording layer and significantly raised the coercivity from 2200 (on the CrMo underlayer) to 3200 Oe. Further increases in the Mn content resulted in the grain growth of the recording layer, and less enhanced coercivity. The doped Zr, Ag, and Nb atoms into CrMo underlayers were segregated and led to reduction of grain size. Among them, Zr doping exhibited the most pronounced effects.