Temperature and Ion Irradiation Dependence of Magnetic Domains and Microstructure in Co/Pt Multilayers

Microstructure and magnetic properties of Co/Pt multilayers with perpendicular anisotropy were studied as a function of growth temperature ( T G ) and ion irradiation. With increased T G , larger columnar grain size and an improved 〉111〈 texture were observed. Up to a critical temperature ( T crit ), a monotonic increase in coercivity ( H C ) with T G was measured, followed by a decrease in H C with further increase in T G . Magnetic domains of films grown below T crit were irregular, with their submicron size decreasing gradually with increasing T G . Films grown at 390°C> T crit had fine domains on the sub-100 nm length scale. Both H C and domain size were reduced after the multilayers were exposed.