A growth model for polycrystalline thin film media: comparison of bicrystal and unicrystal grain structures

A medium model with random grain structure and in-plane grain area distribution has been developed. In this paper, this model is extended to study the grain size distribution of bicrystal thin film media. In most cases, the simulation shows that the grain area distribution to be close to a log-normal distribution. Various combinations of minimum nucleation distances of unicrystal underlayer and bicrystal magnetic layer are investigated. The relative grain area of both layers is investigated by changing the number of nucleation sites. Assuming recombination of adjacent grains with parallel anisotropy axes, the resulting bicrystal grain area distribution width is insensitive to the value of the minimum nucleation distance and only slightly decreases with increasing average area of the bicrystal grains.