Tailoring the Shape, Size, Crystal Structure, and Preferential Growth Orientation of BaTiO₃ Plates Synthesized through a Topochemical Conversion Process

Abstract

The conditions for the topochemical transformation of variously sized Bi 4 Ti 3 O 12 template plates into BaTiO 3 particles were studied in order to control their morphology, crystal structure, and preferential orientation. In the transformation from sub-200 nm-and μm-sized template plates in the presence of surplus BaCO 3 (Bi 4 Ti 3 O 12 /BaCO 3 = 1:10), the final BaTiO 3 particles retained a memory of the precursor size when the conversion reaction in the molten salt (NaCl/KCl) occurred at 660 and 900 °C, respectively. In both cases the side length of the template was well preserved, while the thicknesses of the final BaTiO 3 plates were larger compared to those of the templates. The morphology of the BaTiO 3 particles formed from micrometer-sized Bi 4 Ti 3 O 12 plates at 660 °C did not closely resemble the template shape because of the exfoliation and disintegration processes. Through the transformation of sub-200 nm Bi 4 Ti 3 O 12 plates at 900 °C the formed BaTiO 3 particles grew by Ostwald ripening, and thus also the shape of the final perovskite particles did not retain a memory of the template. We confirmed by Raman spectroscopy and X-ray diffraction that the BaTiO 3 plates formed at 900 °C exhibited a higher tetragonality than those prepared at 660 °C. Ferroelectric hysteresis and piezoelectric butterfly curves, as obtained using a piezo-force microscope, indicated the significant ferroelectric response of [001] preferentially oriented micrometer-sized and sub-micrometer-sized BaTiO 3 plates.

Role of Intrinsic Dipoles in the Evaporation‐Driven Assembly of Perovskite Nanocubes into Energy‐Harvesting Composites

“…From the discussion of experimental results, we conclude that in fact for solubilized ferroelectric BaTiO 3 nanocubes, the polarization screening must be complete without appreciable dipole moment (below a few k B T ), whereas stray interactions from incompletely screened surface charges are likely major sources of disorder in self‐assembled architectures of SrTiO 3 nanocubes. The simulation results are useful to understand the potential sources of disorder in the assembly of core materials for many applications, e.g., the energy‐harvesting composites and photovoltaics, for self‐assembling of BaTiO 3 and related nanoplates …”

Plate-Like Bi4Ti3O12 Particles and their Topochemical Conversion to SrTiO3 Under HydrothermalConditions

“…[6][7][8] Platelike Bi 4 Ti 3 O 12 particles with a side length of around 1 µm and a thickness of 50 nm were formed in molten NaCl/KCl at 800 °C. 9 In contrast to the thickness, the side length of the plates was not uniform, varying from 0.25 µm to 3 µm. He et al systematically studied the influence of the salt/ precursor ratio on the morphology of plate-like Bi 4 Ti 3 O 12 particles prepared in molten salt.…”

“…20,21 Bi 4 Ti 3 O 12 particles were already used for a topochemical conversion to BaTiO 3 or SrTiO 3 in molten salt. 9,22,23 Based on our previous work Bi 4 Ti 3 O 12 is very appropriate template for preparation of BaTiO 3 plate-like particles in the molten salt. 9 To the best of our knowledge, the topochemical conversion from Bi 4 Ti 3 O 12 to BaTiO 3 , Sr-TiO 3 or CaTiO 3 particles under hydrothermal conditions has not yet been reported.…”

Flexible and Ultrasensitive Piezoelectric Composites Based on Highly (00l)‐Assembled BaTiO3 Microplatelets for Wearable Electronics Application

“…[18][19][20][21] Flexible piezoelectric sensor attracted much attention due to its high sensitivity, simple structure, and easy data processing. [35][36][37][38][39] The BT single-crystal microplatelets were widely used as templates to induce (00l) textures in PMN-PT, PMN-PZT, and PIN-PMN-PT ceramics, so that high electromechanical properties could be achieved in these textured piezoceramics. [26,[31][32][33][34] These nanostructured piezoelectric shapes with high anisotropy have displayed high sensitivity because of easier deformation under external forces.…”

“…[22,23] Up to now, many micro/ nanostructure piezoelectric materials such as ZnO nanowires, [24] BaTiO 3 nanowires, [25][26][27] PZT nanowires, [28] PbTiO 3 / ZnO nanobrush, [29] GaN nanowires, [30] Ge/ Si nanowires, and PZT nanorod arrays have demonstrated high sensitivity in electrical responses under small external pressure regimes. [36,[40][41][42][43][44][45] Furthermore, the anisotropic microplatelets have also been applied to reinforce and toughen the polymer-based composite materials. However, the syntheses of nanowires, nanorods, and nanobrushes are usually complicated, expensive, and less productive.…”