SURFACE MODIFICATION AND MAGNETISM IN CO-IMPLANTED BSTO/BARIUM HEXAFERRITE COMPOSITE FILMS

摘要

Composite ferrite-dielectric films are promising electromagnetic materials for a wide variety of tunable applications at RF and microwave frequencies. We have grown Ba_(0.5)Sr_(0.5)TiO_3/BaFe_(12)O_(19) (BSTO/BaM) composite thin films by magnetron sputtering with varying volume fractions of the ferrite and dielectric phases. The M-H hysteresis loops display a distinct double-transition feature in these composites. High energy Co ions were implanted to study the surface modification of the grains and its influence on magnetic properties. Our observations indicate that the effective grain size is reduced and there is a consistent trend in terms of decrease in saturation magnetization and coercivity in the ion-implanted samples when compared with the bare composites.