Dynamic behavior of twins in BaTiO{sub 3}
- Univ. of Washington, Seattle, WA (United States)
The most prominent lattice defects in barium titanate, i.e., twins on two distinct lattice planes {l_brace}111{r_brace} and {l_brace}110{r_brace}, were characterized using dynamic transmission electron microscopy techniques in the image and diffraction modes. In-situ heating experiments from room temperature up to 130 C and then cooling down to {minus}168 C reveal a dependence of {l_brace}110{r_brace} twins on ferroelectric transition. On the other hand, {l_brace}111{r_brace} twins are found to be completely stable through the ferroelectric transition and exist in all phases. Streaking is observed in the diffraction spots leading to an estimation of {l_brace}111{r_brace} twin wall thickness to be about 10{angstrom} while no such streaking was observed corresponding to {l_brace}110{r_brace} twins. Based on these observations and the behavior of the twin boundaries under dynamic heating cycles, an estimate of the twin wall energies indicates that {l_brace}111{r_brace} walls have three orders of magnitude higher energy than that of {l_brace}110{r_brace} walls which explains their relative thermal and mechanical stability.
- OSTI ID:
- 94043
- Report Number(s):
- CONF-941144--; ISBN 1-55899-258-8
- Country of Publication:
- United States
- Language:
- English
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