Fabrication of textured lead-free strontium barium niobate (SBN61) bulk ceramics and their electrical properties

Abstract

Sr0.61Ba0.39Nb2O6 (SBN61) ceramic fibers with a high [001] texture were fabricated by a combination of alginate gelation method and templated grain growth process using acicular Ba2NaNb5O15 (BNN) template particles. The rod-like BNN template particles were prepared by molten salt synthesis method with salt/powder ratio of 2 giving the highest aspect ratio. Fibers were drawn from alginate based slurries without or with 10 wt% BNN template particles. Increasing sintering temperature and time were found to increase the texture. Textured SBN61 bulk ceramics with dimensions in cm scale were fabricated by wet packing a limited number of grain oriented green fibers and sintering the green bulk to obtain a dense, textured bulk ceramic through templated grain growth. A maximum texture fraction, f, of 0.91 was obtained, as measured by Lotgering factor. Increased remnant polarization and electromechanical properties were obtained as a result of this preferred grain orientation. (C) 2016 Elsevier Ltd. All rights reserved.