Switching field variations due to low anisotropy inclusions in disk-shaped magnetic nanostructures with vertical magnetic anisotropy for applications in perpendicular recording bit-patterned medium are analyzed micromagnetically. The influence of various material parameters and geometry on switching field is analyzed. It is found that the size of the low anisotropy inclusion strongly affects the switching field. However, the dependence significantly weakens when inclusions' size becomes comparable to the exchange lengths, also known as domain wall thickness. The location of the inclusion within a bit has only a weak influence on the switching field. Scaling of the bit and the inclusion dimensions result in a system with very similar switching properties. The observed deviations from scalability are attributed to the presence of a non-scalable parameter of micromagnetic models, namely, the domain wall thickness, also known as exchange length. The switching field strongly depends on the bit diameter when the inclusion represents a significant fraction of the bit size-wise. The number of the inclusions in a bit has a relatively weak influence on the switching field, as one inclusion always dominates the magnetization reversal process.
ASJC Scopus subject areas
- Physics and Astronomy(all)