Preparation of Fine Crystalline MnBi Films by Multilayer Structure and their Write-In Characteristics

In this study, the authors attempted to reduce the size of the crystallites of MnBi films through a multilayering process. Three different Bi : Mn ratios and two annealing processes were used. Some of the film samples had Ms and ¿k values equivalent to single layer films, albeit higher Hc. Curie point writing was performed with an external magnetic field of zero and a 25 mW HeNe laser. The pulse widths ranged from 1 ¿s to 10 ¿s, and the laser spot was approximately 2 ¿m in diameter. The size of reversed domains was almost the same as that of the laser spot for pulse widths of 5 to 50 ¿s.