Electronic Resource
[S.l.]
:
American Institute of Physics (AIP)
Journal of Applied Physics
85 (1999), S. 2299-2303
ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Fresnoite, Ba2TiOSi2O7, has been predicted structurally to be a new ferroelectric. Detection of both ac and dc dielectric hysteresis verifies the prediction. The spontaneous polarization Ps estimated from the hysteresis at 1.2 MV m−1 ac is ∼0.2 C m−2 at 295 K, comparable with the minimum Ps observed in one-dimensional ferroelectrics. A reproducible calorimetric anomaly with entropy change 0.19(3) J mol−1 K−1 at 433(2) K in polycrystalline material coincides with a small dielectric and pyroelectric anomaly previously reported in single crystals; an entropy change ∼0.2 J mol−1 K−1 at 810(5) K also accompanies a dielectric anomaly observable in ceramic samples at 805(5) K. Both calorimetric anomalies are ∼60 K wide. Observation of dielectric hysteresis at 875 K shows that neither anomaly corresponds to the Curie temperature; both are likely associated with small changes in atomic position, not with symmetry changes. Melting onset in fresnoite is 1703(1) K with undercooling as deep as 435 K. © 1999 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.369541
| Library |
Location |
Call Number |
Volume/Issue/Year |
Availability |
