Kajewski D, Oh S H, Ko J-H, Majchrowski A, Bussmann-Holder A, Sitko R, Roleder K
Institute of Physics, University of Silesia in Katowice, ul. 75 Pułku Piechoty 1, 41-500, Chorzow, Poland.
School of Nano Convergence Technology, Hallym University, Chuncheon, Gangwondo, 24252, Republic of Korea.
Sci Rep. 2022 Jul 29;12(1):13066. doi: 10.1038/s41598-022-17392-9.
Brillouin light scattering experiments were performed for lead zirconate single crystals doped with niobium. Special attention was paid to the elastic mode softening near phase transition temperatures. The results are compared with data obtained by Raman light scattering experiments. We observed that the interaction between acoustic and optic modes is responsible for symmetry breaking far above T, leading to polar regions' appearance. No changes in the acoustic mode frequency and its damping are observed at T, where ε(T) exhibits a maximum value. The absence of these changes and the central peak observed in Raman experiments suggest that the phase transition at T is mainly of the order-disorder type. The origin of other phase transitions is discussed as well.
对掺铌锆酸铅单晶进行了布里渊光散射实验。特别关注了接近相变温度时弹性模的软化。将结果与拉曼光散射实验获得的数据进行了比较。我们观察到，声学模与光学模之间的相互作用是导致远高于居里温度（Tc）时对称性破缺的原因，从而导致极性区域的出现。在居里温度（Tc）处，当介电常数ε(T)呈现最大值时，未观察到声学模频率及其阻尼的变化。这些变化的不存在以及拉曼实验中观察到的中心峰表明，居里温度（Tc）处的相变主要是有序-无序类型。还讨论了其他相变的起源。
