Lattice transition materials can exist in two phases with different thermal conductivities. Because of this, phase change materials (PCMs) are considered as promising next-generation thermal rectifying materials. The performance of a thermal rectifier known as rectification factor (R) is evaluated by the ratio between the heat that preferentially flows in the forward direction and that in the reverse one. In this work, taking into consideration that PCMs have the striking characteristic of high anisotropy, we propose an analytical framework based on the thermal conductivity tensor theory for predicting the R of lattice transition thermal rectifiers. Because of lattice symmetries, model unveils that the rectification factor is ruled, as well as limited by the ratio of the principal thermal conductivity tensor components present in each phase and the thermal conductivity of the invariant phase material. Furthermore, to validate our predictions the model is applied to the existing experimental systems in the literature, providing accurately truthfulness on observed R. Hence, the analytical model is promising from both theoretical and experimental points of view to understand the effects which allow developing a procedure for engineering an enhanced performance thermal rectifying device.

晶格过渡材料可以以热导率不同的两相存在。因此，相变材料（PCM）被认为是有前途的下一代热整流材料。热整流器的性能称为整流系数（R），是通过优先沿正向流动和反向流动的热量之比来​​评估的。在这项工作中，考虑到PCM具有高各向异性的显着特征，我们提出了一个基于热导张量理论的分析框架来预测R晶格过渡热整流器。由于晶格对称性，模型揭示了整流因子是受支配的，并且受每个相中存在的主要热导张量分量与不变相材料的热导率之比的限制。此外，为了验证我们的预测，该模型被应用于文献中的现有实验系统，从而在观察到的R上提供了准确的真实性。因此，从理论和实验的角度来看，该分析模型都有望了解其效果，从而可以开发出用于设计性能更高的热整流装置的程序。