Fontana Marc D, Kokanyan Ninel, Kauffmann Thomas H
Université de Lorraine, CenraleSupélec, LMOPS, F-57000 Metz, France. Laboratoire Matériaux Optiques, Photonique et Systèmes, CentraleSupélec, Université Paris-Saclay, Metz, 57070, Metz, France.
J Phys Condens Matter. 2020 Jul 1;32(28):285403. doi: 10.1088/1361-648X/ab808e.
The THz and sub-THz polarized Raman response was measured in tetragonal and cubic phases of single domain BaTiO crystal. A large peak was detected at very low wavenumber, within a scattering geometry in which all phonon lines are Raman inactive. It lies below 700 GHz in the whole temperature range of the tetragonal phase, and is clearly distinct from the soft phonon band. This peak has relaxational behavior with a slowing down on approaching the phase transition from above and from below.
在单畴钛酸钡晶体的四方相和立方相中测量了太赫兹和亚太赫兹极化拉曼响应。在非常低的波数处检测到一个大峰，该峰位于所有声子线拉曼非活性的散射几何结构内。在四方相的整个温度范围内，它位于700吉赫兹以下，并且与软声子带明显不同。该峰具有弛豫行为，在从上方和下方接近相变时会减慢。
