Ferroelastic phase in SrBi2Ta2O9 and study of the ferroelectric phase-transition dynamics
Kamba, S. ; Pokorný, J. ; Porokhonskyy, V. ; Petzelt, J.
Woodbury, NY : American Institute of Physics (AIP)
Published 2002
Woodbury, NY : American Institute of Physics (AIP)
Published 2002
| ISSN: |
1077-3118
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| Source: |
AIP Digital Archive
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| Topics: |
Physics
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| Notes: |
Polarized microscope observation of ferroelastic domains in a SrBi2Ta2O9 (SBT) single crystal reveals the presence of domains up to Tc1(similar, equals)770 K, which supports the ferroelasticity and Amam symmetry of the intermediate phase between ferroelectric and paraelectric phases. Far-infrared spectra of SBT ceramics, single crystal and thin films show a well underdamped optical soft mode at 28 cm−1, which partially softens to 21 cm−1 near the ferroelectric transition temperature (Tc2≅600 K). This softening does not explain the entire anomaly of low-frequency permittivity observed near Tc2. On the basis of high-frequency measurements, which do not show a significant dispersion, central-mode-type dispersion in the 10–100 GHz range is proposed as an explanation. So, the phase transition at Tc2 apparently shows a crossover behavior between the displacive and the order–disorder type. © 2002 American Institute of Physics.
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| Type of Medium: |
Electronic Resource
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| URL: |