Effect of BiMeO3 on the Phase Structure, Ferroelectric Stability, and Properties of Lead‐Free Bi0.5(Na0.80K0.20)0.5TiO3 Ceramics. Issue 6 (9th February 2014)

• Record Type: Journal Article
• Authors: Hao, Jigong; Shen, Bo; Zhai, Jiwei; Chen, Haydn; Zhang, S.
• Is Part Of: Journal of the American Ceramic Society. Volume 97:Issue 6(2014)
• Page Start: 1776
• Page End: 1784
• Publication Date: 2014-02-09
• Subjects: Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.12820
• Languages: English
• ISSNs: 0002-7820

Abstract

<abstract abstract-type="main" id="jace12820-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The effects of BiMeO<sub>3</sub> (Me = Fe, Sc, Mn, Al) addition on the phase transition and electrical properties of Bi<sub>0.5</sub>(Na<sub>0.80</sub>K<sub>0.20</sub>)<sub>0.5</sub>TiO<sub>3</sub> (BNKT20) lead‐free piezoceramics were systematically investigated. Results showed that addition of BiFeO<sub>3</sub> into BNKT20 induces a phase transition from tetragonal–rhombohedral coexisted phases to a tetragonal phase with the observation of enhanced piezoelectric properties (<italic>d</italic><sub>33</sub> = 150 pC/N for 0.02BiFeO<sub>3</sub>). BiScO<sub>3</sub>, BiMnO<sub>3</sub>, and BiAlO<sub>3</sub> substitutions into BNKT20 induce a phase transition from coexistence of ferroelectric tetragonal and rhombohedral to a relaxor pseudocubic with a significant disruption of the long‐range ferroelectric order, and correspondingly adjusts the ferroelectric–relaxor transition point <italic>T</italic><sub>F–R</sub> to room temperature. Accordingly, large accompanying normalized strains of 0.34%–0.36% are obtained near the ferroelectric–relaxor phase boundary, and the mergence of large strain response can be ascribed to a reversible field‐induced ergodic relaxor‐to‐ferroelectric phase transformation. Moreover, our study also revealed that the composition located at the ferroelectric–relaxor phase boundary where the strain response is consistently derivable shifts to a BNKT20‐rich composition as the tolerance factor <italic>t</italic> of the end‐member BiMeO<sub>3</sub> increases, and this relationship is expected to provide a guideline for designing high‐performance (Bi<sub>0.5</sub>Na<sub>0.5</sub>)TiO<sub>3</sub>‐based materials by searching the ferroelectric–relaxor phase boundary.</p> </abstract>