The understanding on the interfaces between different polymorphs of nanosized TiO₂ from the perspective of crystallography has great theoretical value for the interface and property design and regulation. In this work, TiO₂ (B)/anatase dual‐phase nanofibers containing different interface structures are investigated in detail. The X‐ray diffraction (XRD) is first employed to illustrate the detailed phase evolution during the calcination under different temperatures. Four types of interfaces with different structures are further studied by transmission electron microscopy (TEM). Single crystal form induced different interfaces is confirmed, which is thought to be the universal conclusion in monoclinic crystal systems. Meanwhile, the other two interface structures in {100} single crystal form are also observed in the samples under higher temperature calcination. Invariant line strain calculation is carried out for the four interfaces. The calculated crystallographic features agree well with the observed results. Furthermore, taken [010]_TB//[001]_TA as the rotation axis, the orientation difference of the single crystal form induced interfaces is confirmed to be 72.5°, corresponding to the β angle of TiO₂ (B). The orientation relationships of the other two interfaces in {100} single crystal form can also be achieved by 7.5° and −4.5° rotation from the interface with the same single crystal form.

中文翻译：

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TiO2（B）/锐钛矿双相纳米纤维中的多种界面结构

从晶体学的角度理解纳米TiO _2的不同多晶型物之间的界面对于界面和性能设计与调控具有重要的理论价值。在这项工作中，TiO ₂（B）/包含不同界面结构的锐钛矿双相纳米纤维已得到详细研究。首先使用X射线衍射（XRD）来说明在不同温度下煅烧过程中详细的相演化。通过透射电子显微镜（TEM）进一步研究了具有不同结构的四种类型的界面。证实了单晶形式引起的不同界面，这被认为是单斜晶体系统的普遍结论。同时，在较高温度煅烧的样品中还观察到{100}单晶形式的其他两个界面结构。对四个接口执行不变线应变计算。计算出的晶体学特征与观察到的结果非常吻合。此外，占[010] _TB//以[001] _TA为旋转轴，可确认单晶形诱导界面的取向差为72.5°，与TiO ₂（B）的β角相对应。{100}单晶形式的其他两个界面的取向关系也可以通过从具有相同单晶形式的界面旋转7.5°和-4.5°来实现。