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Precipitates have recently been found to significantly enhance the mechanical quality factor in piezoelectric ceramics. Such a piezoelectric hardening effect was attributed to strong interactions between ferroelectric domains and precipitates. In the present work, the response of domains to applied electric fields is observed in situ via transmission electron microscopy in aged (Ba, Ca)TiO3 ceramics with precipitates to reveal the underlying mechanism of this phenomenon. Ferroelectric domains in the Ba-rich matrix grain are observed to be more concentrated near non-polar Ca-rich precipitates. With increasing applied voltage, domains separate from precipitates merge together first, while those near precipitates persist to higher voltages. During ramping down, domains nucleate from precipitates. These direct observations confirm the strong interactions between ferroelectric domains and precipitates in piezoelectric ceramics.
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CaTiO3-rich precipitates and their impacts on ferroelectric domains during heating in (Ba,Ca)TiO3 ceramics
In this work with a model system (Ba,Ca)TiO3, we analyze the morphologies of CaTiO3-rich precipitates and their impacts on the microstructures in their surrounding BaTiO¬3-rich matrix. Also, the response of ferroelectric domains around CaTiO3-rich precipitates during heating and cooling is observed in-situ with transmission electron microscopy. Domains attached to precipitates are observed remaining unchanged up to the Curie point at which they disappear. During cooling, domains are observed to form in the vicinity of precipitates and being held in place down to room temperature. Both observations corroborate previous findings that precipitates act as domain pinning points, behaving in a similar manner to earlier experiments with electrical field biasing. Dislocations are often seen around precipitates in the matrix grain and are observed interfering with domains during heating cycles. Dislocations may provide an additional mechanism to restrict domain wall motion and offer a greater piezoelectric hardening effect.
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- Award ID(s):
- 2110264
- PAR ID:
- 10596264
- Publisher / Repository:
- Springer
- Date Published:
- Journal Name:
- Journal of Materials Science: Materials in Electronics
- Volume:
- 35
- Issue:
- 27
- ISSN:
- 0957-4522
- Page Range / eLocation ID:
- 1808
- Subject(s) / Keyword(s):
- In-situ TEM Precipitates Dislocations Piezoelectric Hardening (Ba,Ca)TiO3
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1007/s10854-024-13530-3
