High pressure FAST of nanocrystalline barium titanate
Abstract
Here, this work studies the microstructural evolution of nanocrystalline (<1 µm) barium titanate (BaTiO3), and presents high pressure in field-assisted sintering (FAST) as a robust methodology to obtain >100 nm BaTiO3 compacts. Using FAST, two commercial ~50 nm powders were consolidated into compacts of varying densities and grain sizes. Microstructural inhomogeneities were investigated for each case, and an interpretation is developed using a modified Monte Carlo Potts (MCP) simulation. Two recurrent microstructural inhomogeneities are highlighted, heterogeneous grain growth and low-density regions, both ubiqutously present in all samples to varying degrees. In the worst cases, HGG presents an area coverage of 52%. Because HGG is sporadic but homogenous throughout a sample, the catalyst (e.g., the local segregation of species) must be, correspondingly, distributed in a homogenous manner. MCP demonstrates that in such a case, a large distance between nucleating abnormal grains is required—otherwise abnormal grains prematurely impinge on each other, and their size is not distinguishable from that of normal grains. Compacts sintered with a pressure of 300 MPa and temperatures of 900 °C, were 99.5% dense and had a grain size of 90±24 nm. These are unprecedented results for commercial BaTiO3 powders or any starting powder of 50 nm particlemore »
- Authors:
-
- Univ. of California, Davis, CA (United States)
- Sandia National Lab. (SNL-CA), Livermore, CA (United States)
- Univ. of California, Irvine, CA (United States)
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Publication Date:
- Research Org.:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sandia National Lab. (SNL-CA), Livermore, CA (United States)
- Sponsoring Org.:
- AFRL; USDOE National Nuclear Security Administration (NNSA)
- OSTI Identifier:
- 1341402
- Alternate Identifier(s):
- OSTI ID: 1325373
- Report Number(s):
- SAND-2016-12477J
Journal ID: ISSN 0272-8842; PII: S0272884216308136
- Grant/Contract Number:
- AC04-94AL85000; AC04–94AL85000
- Resource Type:
- Journal Article: Accepted Manuscript
- Journal Name:
- Ceramics International
- Additional Journal Information:
- Journal Volume: 42; Journal Issue: 12; Journal ID: ISSN 0272-8842
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; barium titanate; sintering; grain size; Spark plasma sintering
Citation Formats
Fraga, Martin B., Delplanque, Jean -Pierre, Yang, Nancy, Lavernia, Enrique J., and Monson, Todd C. High pressure FAST of nanocrystalline barium titanate. United States: N. p., 2016.
Web. doi:10.1016/j.ceramint.2016.05.193.
Fraga, Martin B., Delplanque, Jean -Pierre, Yang, Nancy, Lavernia, Enrique J., & Monson, Todd C. High pressure FAST of nanocrystalline barium titanate. United States. https://doi.org/10.1016/j.ceramint.2016.05.193
Fraga, Martin B., Delplanque, Jean -Pierre, Yang, Nancy, Lavernia, Enrique J., and Monson, Todd C. 2016.
"High pressure FAST of nanocrystalline barium titanate". United States. https://doi.org/10.1016/j.ceramint.2016.05.193. https://www.osti.gov/servlets/purl/1341402.
@article{osti_1341402,
title = {High pressure FAST of nanocrystalline barium titanate},
author = {Fraga, Martin B. and Delplanque, Jean -Pierre and Yang, Nancy and Lavernia, Enrique J. and Monson, Todd C.},
abstractNote = {Here, this work studies the microstructural evolution of nanocrystalline (<1 µm) barium titanate (BaTiO3), and presents high pressure in field-assisted sintering (FAST) as a robust methodology to obtain >100 nm BaTiO3 compacts. Using FAST, two commercial ~50 nm powders were consolidated into compacts of varying densities and grain sizes. Microstructural inhomogeneities were investigated for each case, and an interpretation is developed using a modified Monte Carlo Potts (MCP) simulation. Two recurrent microstructural inhomogeneities are highlighted, heterogeneous grain growth and low-density regions, both ubiqutously present in all samples to varying degrees. In the worst cases, HGG presents an area coverage of 52%. Because HGG is sporadic but homogenous throughout a sample, the catalyst (e.g., the local segregation of species) must be, correspondingly, distributed in a homogenous manner. MCP demonstrates that in such a case, a large distance between nucleating abnormal grains is required—otherwise abnormal grains prematurely impinge on each other, and their size is not distinguishable from that of normal grains. Compacts sintered with a pressure of 300 MPa and temperatures of 900 °C, were 99.5% dense and had a grain size of 90±24 nm. These are unprecedented results for commercial BaTiO3 powders or any starting powder of 50 nm particle size—other authors have used 16 nm lab-produced powder to obtain similar results.},
doi = {10.1016/j.ceramint.2016.05.193},
url = {https://www.osti.gov/biblio/1341402},
journal = {Ceramics International},
issn = {0272-8842},
number = 12,
volume = 42,
place = {United States},
year = {Wed Jun 01 00:00:00 EDT 2016},
month = {Wed Jun 01 00:00:00 EDT 2016}
}
Web of Science