Magnetic and Recording Properties of (CoCrPt)$_{1{-}{\rm x}}$ (SiO $_{2}$)$_{\rm x}$ Media

In this work, we report on the determination of the optimum level of SiO
₂
in (CoCrPt)
_1-x
(SiO
₂
)
_x
perpendicular recording media. We have determined the optimum level via studies of magnetic viscosity which have been compared to recording properties. We find that the optimum level of SiO
₂
is of the order of 10%. At this level, studies of the activation volume of reversal show that the grains become essentially exchange decoupled and that a further increase in the level of SiO
₂
produces no further improvement in the decoupling. We also find that this level of SiO
₂
corresponds to optimum recording performance and that increasing the level of SiO
₂
further results in the production of a system with smaller grains where thermal loss is observed to increase dramatically