Crystal optical studies of precursor and spontaneous polarization in PbTiO3
Abstract
High-resolution measurements of the cubic refractive index (RI) of PbTiO3 reveal contributions due to the fluctuating polarization, which attains about 14% of the spontaneous polarization at Tc=769 K. In the tetragonal phase the anomalies of both RI's are shown to be negative with nearly equal amplitude. The nearly vanishing optical anisotropy can be understood in terms of the crystal optical contributions due to tetragonality and to the spontaneous Kerr effect, respectively. A slight nonproportionality of the RI's causes the well-known anomalous temperature dependence of the linear birefringence exhibiting a maximum at 670 K. No evidence is found for another phase transition at low temperatures.
- Publication:
-
Physical Review B
- Pub Date:
- December 1986
- DOI:
- 10.1103/PhysRevB.34.7873
- Bibcode:
- 1986PhRvB..34.7873K
- Keywords:
-
- 64.70.Kb;
- 78.20.Dj;
- 77.80.Bh;
- Solid-solid transitions;
- Phase transitions and Curie point