Structural Explanation of the Dielectric Enhancement of Barium Titanate Nanoparticles Grown under Hydrothermal Conditions
- Condensed Matter Physics and Materials Science Division Brookhaven National Laboratory Upton NY 11973 USA
- Energy Storage Division Interdisciplinary Science Department, Brookhaven National Laboratory Upton NY 11973 USA
- London Centre for Nanotechnology University College London London WC1E 6BT UK
- Photon Sciences Division Brookhaven National Laboratory Upton NY 11973 USA
- Advanced Photon Source Argonne National Laboratory Lemont IL 60439 USA
- Condensed Matter Physics and Materials Science Division Brookhaven National Laboratory Upton NY 11973 USA, London Centre for Nanotechnology University College London London WC1E 6BT UK
When synthesized under certain conditions, barium titanate (BaTiO 3 , BTO) nanoparticles are found to have the non‐thermodynamic cubic structure at room temperature. These particles also have a several‐fold enhanced dielectric constant, sometimes exceeding 6000, and are widely used in thin‐layer capacitors. A hydrothermal approach is used to synthesize BTO nanocrystals, which are characterized by a range of methods, including X‐ray Rietveld refinement and the Williamson–Hall approach, revealing the presence of significant inhomogeneous strain associated with the cubic phase. However, X‐ray pair distribution function measurements clearly show the local structure is lower symmetry than cubic. This apparent inconsistency is resolved by examining 3D Bragg coherent diffraction images of selected nanocrystals, which show the existence of ≈50 nm‐sized domains, which are interpreted as tetragonal twins, and yet cause the average crystalline structure to appear cubic. The ability of these twin boundaries to migrate under the influence of electric fields explains the dielectric anomaly for the nanocrystalline phase.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS); Argonne National Laboratory (ANL), Argonne, IL (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States)
- Sponsoring Organization:
- Engineering and Physical Sciences Research Council (EPSRC); USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC02-06CH11357; SC0012704
- OSTI ID:
- 1962164
- Alternate ID(s):
- OSTI ID: 1961998
OSTI ID: 1962166
OSTI ID: 2281909
- Report Number(s):
- BNL-224140-2023-JAAM; 2208012
- Journal Information:
- Advanced Functional Materials, Journal Name: Advanced Functional Materials Journal Issue: 19 Vol. 33; ISSN 1616-301X
- Publisher:
- Wiley Blackwell (John Wiley & Sons)Copyright Statement
- Country of Publication:
- Germany
- Language:
- English