Effects of an intermediate layer on the magnetic and recording characteristics of CoCrPtTa media.

Effects of bcc and hcp intermediate layers between a bcc–Cr[sub 80]Ti[sub 20] underlayer and a hcp–CoCrPtTa magnetic layer on magnetic and recording characteristics were investigated. The medium without an intermediate layer has a low coercivity H[sub c] of 0.27 kOe due to the perpendicular orientation of the c axis of the CoCrPtTa layer. By introducing a 5-nm-thick intermediate layer of bcc–Cr[sub 60]Mo[sub 40] or hcp–Co[sub 70]Cr[sub 30], the c axis of the CoCrPtTa layer can be effectively in-plane oriented, resulting in a high H[sub c] of 2.71–2.87 kOe and a coercive squareness S[sup *] of 0.72–0.81. The medium with the Cr[sub 60]Mo[sub 40] layer has lower media noise than the medium with the Co[sub 70]Cr[sub 30] layer. This lower noise is considered to be caused by the small grain size of 10.4 nm. The addition of the thin Cr[sub 60]Mo[sub 40] intermediate layer is therefore effective to obtain both high H[sub c] and low noise in the CoCrPtTa media with the CrTi underlayer. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]