Direction of polarization →P and the dipole interaction in the ferroelectric phase of SrTi18O3
Department of Engineering Science, University of Electro-Communications - Chofu-shi, Tokyo 182-8585, Japan
Accepted: 26 April 2011
The structure of isotope-substituted SrTi18O3 (STO18) below Tc=24 K has not been made fully understood yet. We have shown that it is orthorhombic C2v with polarization parallel to c, but other groups reported other structures such as and . In this paper, it is shown that the dipole interaction between the rhombohedral polar clusters which has been revealed by NMR (Blinc R. et al., Phys. Rev. Lett., 94 (2005) 147601) is the very probable reason for the formation of . The dipole interaction model is consistent with various peculiarities observed in the Raman spectra (Shigenari T. et al., Phys. Rev. B, 74 (2006) 174121) such as the inhomogeneity, the imperfect softening and the appearance of the relaxational mode near Tc.
PACS: 77.80.B- – Phase transitions and Curie point / 77.80.Dj – Domain structure; hysteresis / 78.30.-j – Infrared and Raman spectra
© EPLA, 2011