Medium Optimization for Lowering Head Field and Heating Requirements in Heat-Assisted Magnetic Recording

For FePt-L10 granular media, its high anisotropy temperature gradient, dHk/dT, near the Curie temperature is a key motivating factor for its potential high recording area density capability at small grain sizes. The micromagnetic modeling study presented in this letter argues that for today's media with relatively large grain size, if the anisotropy temperature gradient can be relaxed through material engineering, the required head field amplitude and heating can be relaxed while maintaining medium recording signal-to-noise ratio. The study shows that the recording time window holds the key to the optimization of signal-to-noise ratio performance.