Correlation of structural defects and magnetic properties in CoCrPt/Cr and CoCrTaPt/Cr thin films for ultra high density magnetic recording media

Microstructures of high and low coercivity CoCrPt/Cr and CoCrPtTa/Cr were examined. High-coercivity samples were deposited either at high temperatures or with high substrate bias. Low-coercivity samples were deposited at room temperature and at low substrate bias. It was demonstrated that high coercivity films had significantly increased amount of planar faults compared to low-coercivity samples. The faults were identified as densely spaced stacking faults which apparently resulted from the film deformation either during or just after film deposition and they might contribute to higher coercivity due to local changes in crystal anisotropy. An increase in the amount of structural defects by either thermal or impact stress was associated in low-coercivity CoCrPt/Cr films with a profound change of magnetic properties.