Pb(Hf1-xSnx)O3 single crystals with x= 0.23 were characterized using single-crystal X-ray diffraction in the wide temperature range. The information on the structure of two intermediate phases, situated between low temperature antiferroelectric and high temperature paraelectric phases has been obtained. The lower-temperature intermediate AFE2 phase is characterized by incommensurate displacive modulations in the Pb sublattice. The higher temperature intermediate IM phase is characterized by rotations of oxygen octahedra, primarily in the form of anti-phase tilts, which are also present in the lower-temperature AFE2 phase. For the same crystal, 119Sn Mossbauer effect in the temperature range from 300 K to 600 K has been used to study phase transitions mechanism. Two kinds of quadruple splitting have been found. It implies that two different environments of the central Sn ion exist. The observed two kinds of quadruple splitting do not disappear in the whole investigated temperature range which confirm that even far above TC the structure of paraelectric phase is locally non-centrosymmetric.

中文翻译：

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Sn掺杂反铁电PbHfO3单晶的局部性质和相变。

使用单晶 X 射线衍射在宽温度范围内表征 x = 0.23 的 Pb(Hf1-xSnx)O3 单晶。已经获得了位于低温反铁电相和高温顺电相之间的两个中间相的结构信息。低温中间 AFE2 相的特点是 Pb 亚晶格中的位移调制不相称。较高温度的中间 IM 相的特征是氧八面体的旋转，主要以反相倾斜的形式存在，这也存在于较低温度的 AFE2 相中。对于同一晶体，在 300 K 至 600 K 温度范围内的 119Sn Mossbauer 效应已被用于研究相变机制。已经发现了两种四重分裂。这意味着中心 Sn 离子存在两种不同的环境。观察到的两种四重分裂在整个研究温度范围内都没有消失，这证实了即使远高于 TC，顺电相的结构也是局部非中心对称的。