【摘要】 BaZrO₃是新一代钙钛矿型热障涂层材料，采用非平衡分子动力学（NEMD）方法，在1 000 K下，对不同条件下的BaZrO₃薄膜热导率进行研究.结果表明：在温度一定的情况下，BaZrO₃薄膜厚度由5.05 nm增加到13.48 nm时，热导率从1.313 Wm^-1K^-1增加到1.723 Wm^-1K^-1,呈现出明显的尺寸效应；薄膜厚度为5.05 nm, Ca掺杂浓度由0.052%增加到1.302%时，BaZrO₃薄膜热导率从1.26 Wm^-1K^-1降低到了0.983 Wm^-1K^-1.从中可以看出，BaZrO₃材料低维化和掺入Ca所产生的缺陷和畸变都会使其热导率降低.分析讨论了薄膜厚度和Ca掺杂浓度对BaZrO₃热导率的影响，并与已有的实验研究结果进行对比，进一步证明研究结果的合理性.该研究为BaZrO₃在热障涂层材料领域的应用提供了重要的理论依据.更多还原

【Abstract】 BaZrO₃ is a new generation of perovskite thermal barrier coating materials, and the non-equilibrium molecular dynamics（NEMD） method was used to study the thermal conductivity of BaZrO₃ films under different conditions at 1000 K. The results show that as the thickness of BaZrO₃ film increases from 5.05 nm to 13.48 nm at a certain temperature, the thermal conductivity increases from 1.313 Wm^-1K^-1 to 1.723 Wm^-1K^-1, showing an obvious size effect. When the thickness of the film is 5.05 nm and the Ca doping concentration increases from 0.052% to 1.302%, the thermal conductivity of BaZrO₃ film decreases from 1.26 Wm^-1K^-1 to 0.983 Wm^-1K^-1. It can be seen that the thermal conductivity of BaZrO₃ material is reduced due to the defects and distortions caused by the low-dimensionality and the incorporation of Ca. In this paper, the effects of film thickness and Ca doping concentration on the thermal conductivity of BaZrO₃ are analyzed and discussed, and compared with the existing experimental results, the rationality of the research results is further proved. This study provides an important theoretical basis for the application of BaZrO₃ in the field of thermal barrier coating materials.更多还原