Ferroelectrics with perovskite‐like layered (PL) structure are well‐known for their high T_c and the application prospect of high‐temperature‐piezoelectric sensing. In this study, the PL‐structure Eu₂Ti₂O₇ was prepared by 1‐step high‐pressure sintering, which show the pyrochlore structure of Eu₂Ti₂O₇ would change into PL structure at 11 GPa, 1300°C. The PL‐structure Eu₂Ti₂O₇ is metastable, which will change back to pyrochlore structure at about 900°C in the air. The PL‐structure Eu₂Ti₂O₇ was confirmed as a high‐temperature ferroelectric material for the first time. The ferroelectric domain switching was directly observed using piezoelectric force microscope. The piezoelectric constant of the PL Eu₂Ti₂O₇ ceramic was measured as 0.7‐0.9 pC/N and its thermal depoling temperature (T_d) was determined as 800°C, which is associated with the PL‐pyrochlore transition.

中文翻译：

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Eu2Ti2O7在高压下的相变和具有钙钛矿状层状结构的新铁电相

具有钙钛矿状（PL）层状结构的铁电体以其较高的T _c和高温压电传感的应用前景而闻名。在本研究中，通过1步高压烧结制备了PL结构的Eu ₂ Ti ₂ O ₇，这表明Eu ₂ Ti ₂ O ₇的烧绿石结构将在1300°C的11 GPa下转变为PL结构。PL结构的Eu ₂ Ti ₂ O ₇是亚稳态的，它将在约900°C的空气中变回烧绿石结构。PL结构Eu ₂ Ti ₂ O ₇首次被确认为高温铁电材料。使用压电力显微镜直接观察铁电畴的切换。测得PL Eu ₂ Ti ₂ O ₇陶瓷的压电常数为0.7-0.9 pC / N，测得的热极化温度（T _d）为800°C，这与PL-烧绿石的转变有关。