Centrifugal sintering of a barium titanate thick film

A highly packed barium titanate film with a thickness of 30 μm was prepared under 1000 g_n (g_n, standard acceleration of free fall) via centrifugal sintering. Here, BaTiO₃ particles were used as the source material, and LiF flux was co-added as a grain growth enhancer. The film was originally printed on a substrate by screen printing, and subsequently sintered. As the amount of flux increased, the film density also increased with remarkable grain growth. However, it was difficult to remove pores in conventional sintering even by the heavy addition of flux such as 20 wt%. In contrast, centrifugal sintering successfully compacted films (90% of theoretical density). The centrifugally sintered film possessed a relatively smooth surface and showed no flux segregation. These features of a centrifugally sintered film are thought to be attributed to the enhancement of particles' rearrangement at an elevated temperature by a centrifugal force.