High piezoelectric response in the new coexistent phase boundary of 0.87BaTiO3–(0.13-x)BaZrO3–xCaTiO3

• Published in: Materials & design Vol. 86; pp. 564 - 574
• Main Authors: Sutapun, Manoon, Vittayakorn, Wanwilai, Muanghlua, Rangson, Vittayakorn, Naratip
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 05-12-2015
• Subjects: BaTiO3; BaZrO3; Boundaries; CaTiO3; Ceramics; Design engineering; Electric fields; Lead-free piezoelectric; Phase boundaries; Phase transition; Piezoelectricity; Softening; Strain; BaZrO3; Lead-free piezoelectric; CaTiO3; BaTiO3; Phase transition
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2015.07.172

An investigation of the coexistent ferroelectric phase was carried out on the ternary system of 0.87BaTiO3–(0.13-x)BaZrO3–xCaTiO3 [abbreviated as BT–BZ–xCT (where 0.00≤x≤0.13)]. Temperature-, frequency-dependent dielectric data, electric field-dependent strain and polarization as a function of composition are presented in order to understand the relationships of structure-properties and find the high piezoelectric response in this system. Results showed that ceramics in the composition range of 0.00≤x<0.04 were of a rhombohedral structure and transformed into a tetragonal structure at x>0.06. The multiphase coexistence of the rhombohedral and tetragonal phase in this system was identified at x=0.06. A large, virtually hysteresis-free electric field induced strain of 0.23% was achieved with the composition, x=0.06, at 40kV/cm on the boundary between rhombohedral and tetragonal phase. This relates to an extraordinarily high and normalized piezoelectric coefficient (Smax/Emax) of 1280pm/V, which was reached at a low electric field applied at 10kV/mm. These results indicated that a high piezoelectric response may stem primarily from the rhombohedral-tetragonal phase boundary, due to greater lattice softening and reduced energy barriers for polarized rotation.
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•The new coexistent phase composition in the 0.87BaTiO3–(0.13-x)BaZrO3–xCaTiO3 system was identified.•A high normalized piezoelectric coefficient (Smax/Emax) of 1260pm/V was achieved at the coexistent phase composition.•A composition–temperature ferroelectric phase diagram was proposed in this work.