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 (TG) and ion irradiation. With increased TG, larger columnar grain size and an improved 〈111〉 texture were observed. Up to a critical temperature (Tcrit), a monotonic increase in coercivity (HC) with TG was measured, followed by a decrease in HC with further increase in TG. Magnetic domains of films grown below Tcrit were irregular, with their submicron size decreasing gradually with increasing TG. Films grown at 390 °C>Tcrit had fine domains on the sub-100 nm length scale. Both HC and domain size were reduced after the multilayers were exposed.