We present an ultrasonic study of relaxor-based solid solution (1−x) PbFe2/3W1/3O3–x PbTiO3 (0.25 ≤ x ≤ 0.35) located within the morphotropic phase boundary (MPB). The longitudinal ultrasonic wave velocity and attenuation have been measured by the ultrasonic pulse-echo technique at a frequency of 10 MHz in a wide temperature range from 200 to 800 K. Attenuation peaks have been observed at characteristic temperatures, namely, at Burns temperature TB and the additional distinctive temperature T*. To explain the experimental results, we consider a modified polar nanoregions (PNRs) model taking into account fluctuation corrections of ultrasonic wave velocity and attenuation in the vicinity of both TB and T*. The obtained results confirm the dynamic nature of MPB effects which determine the physical properties of relaxor-based solid solutions.

中文翻译：

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PbFe2/3W1/3O3–PbTiO3 固溶体中同向性相边界附近弛豫温度特性的超声证据

我们对位于同形相界 (MPB) 内的基于弛豫的固溶体 (1-x) PbFe2/3W1/3O3-x PbTiO3 (0.25 ≤ x ≤ 0.35) 进行超声研究。在 200 到 800 K 的宽温度范围内，通过超声脉冲回波技术在 10 MHz 频率下测量了纵向超声波速度和衰减。在特征温度下观察到了衰减峰值，即在烧伤温度 TB 和额外的独特温度 T*。为了解释实验结果，我们考虑了改进的极性纳米区 (PNR) 模型，同时考虑了 TB 和 T* 附近超声波速度和衰减的波动校正。获得的结果证实了 MPB 效应的动态性质，它决定了基于弛豫的固溶体的物理性质。