Laser irradiation effect on carbon overcoat for HAMR application

Heat-assisted magnetic recording (HAMR) applies a laser beam to heat the disk magnetic recording unit in a hard drive. It lowers the coercivity of the recording material temporarily before data writing and thus overcomes the superparamagnetic limit. This approach can largely increase the storage density of hard disk drives. To apply it to current hard disk drive, all data recording component including carbon overcoats on hard disk surfaces should have high thermal stability because any degradation or film diffusion may affect the drive performance. To explore HAMR application suitable carbon overcoats, this paper studies the HAMR laser effect on different hard disk carbon overcoats and discusses the related material property change mechanism. Copyright © 2014 John Wiley & Sons, Ltd.