Barium Hexaferrite Thick Films Made by Liquid Phase Epitaxy Reflow Method

In this work, we report on the growing of BaFe$_{12}$O$_{19}$(or BaM) thick films on (0001) sapphire Al$_{2}$O$_{3}$ substrate. Our goal is to fabricate barium ferrite thick films which can be self-biased for circulator application. We have modified the liquid phase epitaxy (LPE) method by conducting the experiment in vacuum. A small chunk piece of the melt weighing about 0.035 g was placed on 1cm x 1cm Al$_{2}$O$_{3}$ substrate and remelted at 1200$^{\circ}$C for one hour. The thickness of our thick films grown by this reflow method range from 300 to 550 $\mu$m. The coercivities of the thick films in the perpendicular direction were about 100Oe.