Simple modeling of readback response based on granular micro-structure

Magnetization transitions, readback waveforms, and transition jitter are formulated for Voronoi modeling using error functions. Suitable coefficients for the error functions are provided by the parameters of the granular media, i.e., average grain diameter and grain size distribution. TEM images of real media are used to confirm the fitted results. Random grain positions and uniform switching field distribution are assumed. Readback waveforms for isolated transitions are calculated by reciprocity. The pulse width, T₅₀, is formulated from the medium parameters and readback conditions. An error function with the same T₅₀ and slope at the transition center is a good fit. An analytical expression for jitter noise is presented comprising grain size and track width parameters.