Growth of (Na0.5Bi0.5)TiO3-SrTiO3 single crystals by solid state crystal growth

• Published in: Ceramics international Vol. 42; no. 16; pp. 18894 - 18901
• Main Authors: Lee, Daeki, Vu, Hung, Sun, Hengyang, Pham, Thuy Linh, Nguyen, Dang Thanh, Lee, Jong-Sook, Fisher, John G.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2016
• Subjects: Dielectric properties (C); Lead-free piezoelectric; Microstructure-final (B); Perovskites (D); Dielectric properties (C); Lead-free piezoelectric; Microstructure-final (B); Perovskites (D)
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2016.09.038

Single crystals of 0.8(Na0.5Bi0.5)TiO3-0.2SrTiO3 were grown for the first time by the Solid State Crystal Growth technique (SSCG). [001], [110] and [111]-oriented seed crystals of SrTiO3 were buried in 0.8(Na0.5Bi0.5)TiO3-0.2SrTiO3 powder which was then pressed to form samples. Samples were sintered at 1200°C for 20h and single crystals of 0.8(Na0.5Bi0.5)TiO3-0.2SrTiO3 grew on the seeds. The direction of least growth was [001] (∼60µm), with the [110] and [111] directions having growth distances of ∼200µm. Chemical composition of the crystals was analyzed by Electron Probe Micro Analysis and found to be close to the nominal composition, with some volatilization of Na and Bi. Micro-Raman scattering showed that the single crystal has the (Na0.5Bi0.5)TiO3 structure. In order to measure the electrical properties, a single crystalline thick film of 0.8(Na0.5Bi0.5)TiO3-0.2SrTiO3 was grown on a [001]-oriented Nb-doped SrTiO3 seed crystal. The single crystalline thick film showed relaxor-like relative permittivity vs. temperature behavior and polarization – electric field hysteresis loops for a lossy ferroelectric material.