The solid-state reaction and diffusion behaviors of CaFe₂O₄ and TiO₂ were investigated using a diffusion couple method at 1373 K to 1473 K under air atmosphere, and an in situ XRD method was used to analyze the solid-state reaction process. The reactions between calcium ferrite and TiO₂ in the solid state are displacement reactions that produce perovskite and Fe₂O₃. The diffusion interface was divided into three layers based on phase analysis: layer I was composed of CaTiO₃; layer II was composed of Fe₂O₃, CaTiO₃, CaFe₂O₄, and Ca₂Fe₂O₅; and layer III was composed of CaTiO₃, Fe₂O₃, CaFe₂O₃, and CaFe₄O₇. The interface was formed in three stages. In stage I, CaTiO₃ formed at the interface. In stage II, the gradual thickening of layers I and II was accompanied by the growth of the amount of CaTiO₃ phase. In stage III, CF decomposed into CF₂, and layer III formed. Micropores were formed in layer II due to the Kirkendall effect, and the diffusion rate of Ca²⁺ in CaFe₂O₄ was greater than that in CaTiO₃. The squared thickness of layer I was found to depend linearly on time, and the expression for predicting the thickness of layer I was proposed:

采用Cafe ₂ O ₄和TiO ₂的固相反应和扩散行为，在大气气氛下于1373 K至1473 K下采用扩散耦合法进行了研究，并采用原位XRD方法对固相反应过程进行了分析。固态的铁氧体钙和TiO ₂之间的反应是置换反应，产生钙钛矿和Fe ₂ O ₃。根据相分析，将扩散界面分为三层：第一层由CaTiO ₃组成；第二层由CaTiO ₃组成。第二层由Fe ₂ O ₃，CaTiO ₃，CaFe ₂ O组成₄和Ca ₂ Fe ₂ O ₅ ; 第三层由CaTiO ₃，Fe ₂ O ₃，CaFe ₂ O ₃和CaFe ₄ O _7组成。界面分为三个阶段。在阶段I中，在界面处形成CaTiO ₃。在阶段II中，层I和II的逐渐增厚伴随着CaTiO ₃相量的增长。在阶段III中，CF分解为CF ₂，并且形成层III。由于柯肯德尔效应和Ca ²⁺在CaFe _2中的扩散速率，在第二层中形成了微孔O ₄大于CaTiO ₃中的O ₄。发现层I的平方厚度与时间呈线性关系，并提出了预测层I厚度的表达式：