Multilayer regular hexagonal prism barium ferrite nanodot arrays on a substrate based on an AAO mask

Highlights: • The BaM nanodot is multilayer regular hexagonal prism structure. • The arrays have a high squareness ratio of 0.65 along the easy magnetization direction. • The nanodots have a small interactive field between the particles. Herein, the multilayer regular hexagonal barium ferrite nanodot arrays have been prepared by pulsed laser deposition through a porous anodic alumina template. The BaM nanodot arrays displayed a c-axis oriented crystal with a multilayer regular hexagonal structure, and the degree of orientation was improved by the post-annealing. Furthermore, the hysteresis loops showed the annealed nanodot arrays have a high squareness ratio of 0.65 along the easy magnetization direction. The first-order reversal curve diagram confirmed that the nanodots have a small interactive field between the particles. Consequently, this effective approach is potentially applied in self-biased microwave devices.