Occurrence of a new superlattice phase across the antiferroelectric phase transition in Sr1−xCaxTiO3 (x = 0.30 and 0.40)
IR@CECRI: CSIR-Central Electrochemical Research Institute, Karaikudi
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Title |
Occurrence of a new superlattice phase across the antiferroelectric phase transition in Sr1−xCaxTiO3
(x = 0.30 and 0.40)
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Creator |
Anwar, S.
Lalla, N.P. |
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Subject |
Electrochemical Materials Science
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Description |
Low-temperature x-ray diffraction, low-temperature transmission electron microscopy (TEM)
and dielectric permittivity studies have been carried out on Sr1−xCax TiO3 (x = 0.30 and 0.40)
ceramics across its antiferroelectric phase transition. TEM has been performed for its structural
and microstructural characterizations. Together with the occurrence of the usual structural
modulation along [001] of the P21212 (and Pbnm), which gives rise to the Pbcm phase, clear
evidences of the occurrence of a new phase, appearing as a result of structural modulation along
the [110]-type direction of the Pbnm, has also been found. The temperature dependent
dielectric permittivity data appears to indicate the paraelectric nature of the new phase. The
coexistence of this new phase with the Pbcm phase has been attributed to �-point instability,
which is equally probable along any of the [100]-type directions of the basic perovskite
structure. It appears that irrespective of the existing perovskite distortion, which results in
P21212 for x = 0.3 and Pbnm for x = 0.4; the �-point instability follows the cubic symmetry
of the very basic perovskite
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Publisher |
IOP Publishing Ltd.
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Date |
2008
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Type |
Article
PeerReviewed |
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Format |
application/pdf
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Identifier |
http://cecri.csircentral.net/373/1/112-2008.pdf
Anwar, S. and Lalla, N.P. (2008) Occurrence of a new superlattice phase across the antiferroelectric phase transition in Sr1−xCaxTiO3 (x = 0.30 and 0.40). Journal of Physics: Condensed Matter, 20 (32). ISSN 0953-8984 |
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Relation |
http://cecri.csircentral.net/373/
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