10.1021/acs.cgd.8b00596.s001 Gabriel Buse Gabriel Buse Cong Xin Cong Xin Pascal Marchet Pascal Marchet Ana Borta-Boyon Ana Borta-Boyon Mai Pham-Thi Mai Pham-Thi Hughes Cabane Hughes Cabane Emmanuel Veron Emmanuel Veron Michael Josse Michael Josse Matias Velazquez Matias Velazquez Michel Lahaye Michel Lahaye Eric Lebraud Eric Lebraud Mario Maglione Mario Maglione Philippe Veber Philippe Veber Spinodal Decomposition in Lead-free Piezoelectric BaTiO<sub>3</sub>–CaTiO<sub>3</sub>–BaZrO<sub>3</sub> Crystals American Chemical Society 2018 charge coefficient solution growth indistinctly polycrystals chemical analysis Zr content P 4 mm BaZrO spinodal decomposition mechanism perovskite structures Spinodal Decomposition partition coefficients Castaing microprobe measurements Polycrystalline samples pc Zr element content variation zirconium contents Curie temperatures CaTiO Rietveld measurements centimeter-sized BaTiO 3 miscibility gap Amm 2 space groups phase periodical Zr room temperature 2018-09-06 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Spinodal_Decomposition_in_Lead-free_Piezoelectric_BaTiO_sub_3_sub_CaTiO_sub_3_sub_BaZrO_sub_3_sub_Crystals/7100663 Polycrystals and centimeter-sized BaTiO<sub>3</sub>-based single crystals were grown by top seeded solution growth from the BaTiO<sub>3</sub>–CaTiO<sub>3</sub>–BaZrO<sub>3</sub> system. High effective partition coefficients of Zr ranging from 15 to 6 with small Zr content have been calculated from Castaing microprobe measurements, whereas those of Ca increase slightly from 0.45 to 0.7. A spinodal decomposition mechanism is emphasized during the growth leading to the emergence of two phases with close compositions. Chemical analysis displayed periodical Zr and Ca content fluctuations within the whole boules, and Rietveld measurements highlighted two phases belonging to perovskite structures with tetragonal <i>P</i>4<i>mm</i> and orthorhombic <i>Amm</i>2 space groups. Samples with various calcium and zirconium contents were characterized by means of dielectric and piezoelectric measurements. Most efficient samples are indistinctly polycrystals or oriented single crystals where electromechanical performances are compositional-dependent. Polycrystalline samples and single crystals oriented along (001)<sub>pc</sub> and (110)<sub>pc</sub> displayed Curie temperatures ranging from 50 to 111 °C. Electromechanical coupling factor up to 58% and piezoelectric charge coefficient <i>d</i><sub>33</sub> = 496 pC·N<sup>–1</sup> were obtained at room temperature. The miscibility gap between the two perovskite solid solutions as well as Ca and Zr element content variation in single crystals lower crystal piezoelectric response that remains nonetheless of the same efficiency compared to that of ceramics of the same composition.