Postannealing effects on magnetic properties and microstructure of CoCrPt/Ti perpendicular recording media

In this work, we investigate the postannealing effects on the magnetic and structural properties of CoCrPt perpendicular films. We observe a coercivity of 5000 Oe in the films with a 2 nm CrMn overlayer, which is about two times larger than the coercivity of similar films without a CrMn overlayer. This increment is attributed to the decoupling of grains by diffusion of CrMn from the top layer through the grain boundaries. An increase in the negative nucleation field and a decrease in intergranular exchange coupling with annealing temperatures was observed for the films with a CrMn overlayer. On the other hand, the films without a CrMn overlayer show the opposite trends except at high annealing temperature (450 degreesC). We observe a coercivity of similar to7600 Oe and a negative nucleation field of similar to2400 Oe for a film with a CrMn overlayer annealed at 450 degreesC for 5 min. (C) 2003 American Institute of Physics.