Origin of incoherent magnetic switching behavior in CoCrPt-SiO_2 perpendicular magnetic recording media

摘要

Magnetic switching behavior for CoCrPt-SiO_2 single layer media with oxygen contents (OCs) from 4% to 10% and recording layer thickness (t_(mag)) from 2 to 27 nm is investigated. Significant incoherent switching, caused by domain wall motion, and large activation volume are observed at t_(mag) ≤ 6 nm regardless of OC, consistent with nonuniform microstructure with less grain isolation at t_(mag) = 4 nm. These results support formation of a highly exchange-coupled thin magnetic layer on top of Ru interlayer, which can explain the large difference between angular dependence of H_(cr) predicted by the Stoner-Wohlfarth theory and the experimental values.