Affiliation:
1. School of Materials Science and Engineering Nanyang Technological University Singapore Singapore
2. College of Physics and Information Engineering Fuzhou University Fuzhou China
3. FZU‐Jinjiang Joint Institute of Microelectronics Jinjiang Science and Education Park Fuzhou University Jinjiang China
Abstract
AbstractSintering for large‐sized, stoichiometric Bi0.5Na0.5TiO3 (BNT) ceramics is of great challenge due to the loss of volatile Bi/Na at A‐site of perovskite structure. In this work, BNT ceramic tile with the size of ∼10 × 10 cm2 and near‐stoichiometric composition has been successfully fabricated by Isobam‐assisted gelcasting process, followed by sintering with 1150°C calcined power bed. The powder bed used and sintering duration were found to have a great influence on the formation of the Na‐deficient phase (Bi4.5Na0.5Ti4O15) in the ceramics, and the strategies to eliminate it have been explored. The obtained ceramics exhibit a dielectric constant/loss of 673.6/0.039 at 1 kHz, as well as an electrostrictive strain of ∼0.07% which corresponds to a converse piezoelectric constant of 105.2 pm/V. Our work thus provides an effective approach to prepare large‐sized and stoichiometric BNT ceramics.
Subject
Materials Chemistry,Ceramics and Composites