Magnetic reversal phenomena in pseudo-spin-valve films with perpendicular anisotropy

摘要

Perpendicular pseudo-spin-valve films with structure Ti/CoCrPt/Ti/CoCrPt were fabricated by UHV sputtering. The Ti serves both as a seed layer, to promote a perpendicular c-axis orientation, and as a spacer between the magnetic layers. The films show characteristic two-step switching with a wide plateau corresponding to antiparallel alignments of the magnetic layers. For a 5 nm Ti/5 nm CoCrPt/5 nm Ti/20 nm CoCrPt, antiparallel alignment exists between 70 and 345 Oe. Minor loops demonstrate switching of the thin layer, in addition to time-dependent magnetization reversal attributed to creep in the magnetization as a result of growth of reversed domains. Magnetic force microscopy and time-dependent magnetization measurements suggest that the domain propagation field is lower than the field necessary for domain nucleation.