Demonstration of Perfect Softening of the Slater-Type Ferroelectric Mode on SrTi¹⁸O₃

Abstract

The perfect softening of the ferroelectric E _u mode has been demonstrated in SrTi ¹⁸ O ₃ by Raman scattering using a Sandercock-type tandem Fabry-Perot interferometer. The temperature dependence of the E _u mode spectrum indicates that the mechanism of the ferroelectric phase transition is concluded as the ideal displacive type related to the Slater-type ferrlelectric mode. The observed result is compared to the previous reported results observed by a hyper-Raman scattering, inelastic neutron scattering, and Raman scattering.

Keywords:

• Perfect softening
• ferroelectric phase transition
• soft mode dynamics
• Raman scattering
• displacive type
• STO¹⁸

Acknowledgment

This work was partially supported by a Grant-in-Aid for Scientific Research (B) from JSPS No. 17340088 (M.T.), a Grant-in-Aid for Scientific Research (S) from JSPS No. 17104004 (T.Y.) and the 21st COE program on “Topological Science and Technology” at Hokkaido University from MEXT.