Spin-Stand Measurements to Extract the Switching Distributions of Heat-Assisted Magnetic-Recording Media

A new measurement method to characterize the switching temperature distributions of heat-assisted magnetic recording (HAMR) media at recording time scales is presented. The method uses HAMR components in conventional recording systems, such as spin-stand testers and hard disk drives. Using dc noise measurements, a 2-D map of the probability of grains switching is extracted as a function of the medium temperature and of the applied field, which are controlled by the HAMR head laser power and writer current, respectively. These measurements give access to details of the HAMR media temperature and field distributions, as well as provide useful information related to the operation of the HAMR system.