Separate quantitative evaluation of degree of order and perpendicular magnetic anisotropy for disorder and order portion in FePt granular films

The dependence of the degree of order and perpendicular magnetic anisotropy (K-u perpendicular to) on magnetic layer thickness (d(mag)) for FePt granular films with various grain boundary materials (GBMs) were investigated. According to the analysis for granular films with a constant GBM volume of 30 vol%, the order, disorder, and non-epitaxial portions co-existed in the FePt granular films. From the separate quantitative evaluation for these portions, the following was found; 1) the degree of order and magnitudes of K-u perpendicular to for disorder and order portions against d(mag) were constant, while the film average evaluation resulted in the dependence of the degree of order and K-u perpendicular to on d(mag) and the positive correlation between the grain diameter and the degree of order, 2) for the order portion, K-u perpendicular to had linear correlation with the degree of order, 3) the magnitude of K-u perpendicular to and the degree of order for the order portion depended on GBM.

Automated summary

The study revealed that the degree of order and perpendicular magnetic anisotropy in FePt granular films are influenced by the thickness of the magnetic layer and the grain diameter, as well as by the specific grain boundary material used.