Effects of CrNi pre-layer on magnetic properties of CoCrTa longitudinal media

We have found that higher coercivity can be achieved on CoCrTa/Cr films by introducing a CrNi pre-layer between underlayer Cr and NiP plated layer. Coercivity is dependent on the Ni content in CrNi layer, and shows a maximum at Ni=40at%. Comparing crystallographic texture and microstructure of the media with and without Cr/sub 60/Ni/sub 40/ pre-layer, we concluded that the increase of coercivity is attributed to a reduced intergranular magnetic coupling.