More and more evidence points out the coexistence of displacive and order-disorder dynamics in the phase transition of barium titanate. Here, we report an initial state determined phase transition in barium titanate by applying second harmonic generation technology and piezoresponse force microscopy (PFM). The out-of-plane PFM results of these barium titanate crystals show the increase in domain walls in the surfaces after annealing, leading to the increase in the second harmonic signal measured. This work directly revealed how the displacive and order-disorder dominate the phase transition and what the role is that the domain wall plays in this process.More and more evidence points out the coexistence of displacive and order-disorder dynamics in the phase transition of barium titanate. Here, we report an initial state determined phase transition in barium titanate by applying second harmonic generation technology and piezoresponse force microscopy (PFM). The out-of-plane PFM results of these barium titanate crystals show the increase in domain walls in the surfaces after annealing, leading to the increase in the second harmonic signal measured. This work directly revealed how the displacive and order-disorder dominate the phase transition and what the role is that the domain wall plays in this process.

中文翻译：

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通过二次谐波产生探测钛酸钡晶体中温度相关的相变

越来越多的证据指出钛酸钡相变过程中位移和有序-无序动力学并存。在这里，我们通过应用二次谐波生成技术和压电响应力显微镜 (PFM) 报告了钛酸钡中初始状态确定的相变。这些钛酸钡晶体的面外 PFM 结果显示退火后表面畴壁增加，导致测量的二次谐波信号增加。这项工作直接揭示了位移和有序-无序如何主导相变以及畴壁在这个过程中的作用。越来越多的证据指出在钡的相变中位移和有序-无序动力学并存钛酸盐。这里，我们通过应用二次谐波产生技术和压电响应力显微镜 (PFM) 报告了钛酸钡中初始状态确定的相变。这些钛酸钡晶体的面外 PFM 结果显示退火后表面畴壁增加，导致测量的二次谐波信号增加。这项工作直接揭示了位移和有序-无序如何主导相变以及畴壁在此过程中的作用。