Fabrication of orientation-controlled bismuth-layer-structured ferroelectric ceramics by rolling-extended method and their piezoelectric properties

Abstract

As a new technique to fabricate bismuth-layer-structured ferroelectric ceramics having a large size in the direction of c-axis orientation, the rolling-extended orientation method was developed. The green compacts having a large size in c-axis were easily obtained with lower lamination by piling up thicker uniaxially-oriented green sheets, which were fabricated by the rolling-extended orientation method. The rectangular bars having c-axis along their length direction were cut out of the green compacts. The relationships between the orientation degree and the fabrication conditions, such as the repetition number of the rolling-extended process, the size and the concentration of the templates in green sheets, were studied. The piezoelectric properties were compared between two rectangular samples having c-axis along their length direction and width direction.