Microstructure of co-evaporated CoCr films with perpendicular anisotropy

Co-evaportation of Co and Cr is applied to achieve good magnetic characteristics of the media deposited at low temperature. The opposed oblique incidence vapour flux induces a columnar alignment parallel to the evaporation plane. Further a process-induced segregation is present which introduces separated Co-rich and Cr-rich regions. A selective etching process is carried out to find proof of this. The large increase on Ms with respect to those of a homogeneous bulk CoCr layer with the same average composition confirms this. The columns, texture axes and Kj axes are inclined toward the Co source, which was the main vapour flux direction. With increasing process temperature the tilting decreases.