Abstract The temperature dependences of the dielectric permittivity and dielectric loss tangent in the ferroelectric ceramic Ba0.8Sr0.2TiO3 have been studied at frequencies from 25 Hz to 120 Hz. It was found that the phase transition at the Curie point (ТС ≈ 338 K) is diffused in the temperature range of ∼ 30 K. The temperature dependence of the local order parameter plotted based on dielectric measurement data confirms the diffusion of the phase transition, which begins by the arising of local polar regions at Burns temperature. The revealed dependences of the dielectric loss maximum near the TC on the heating rate of the sample and frequency are well explained in the framework of the fluctuation model of low-frequency dielectric losses during a first-order phase transitions.

中文翻译：

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铁电陶瓷Ba0.8Sr0.2TiO3居里点相变动力学

摘要 研究了铁电陶瓷 Ba0.8Sr0.2TiO3 在 25 Hz 至 120 Hz 频率下的介电常数和介电损耗角正切的温度依赖性。发现居里点 (ТС ≈ 338 K) 的相变在 ~ 30 K 的温度范围内扩散。基于介电测量数据绘制的局部有序参数的温度依赖性证实了相变的扩散，这始于在伯恩斯温度下局部极地地区的出现。在一阶相变期间低频介电损耗波动模型的框架中，很好地解释了 TC 附近介电损耗最大值对样品加热速率和频率的依赖性。