Abstract Zirconia (ZrO2) and zircon (ZrSiO4) have high strengths and stabilities at high temperatures and also have remarkable thermal properties, such as rather low thermal conductivities. In the present research, the phonon thermal conductivity of zircon and two polymorphs (cubic and monoclinic phases) of zirconia are investigated. For this purpose, equilibrium molecular dynamics simulations using classical interatomic potentials and the Green-Kubo formalism are presented. The results are given in detail over a wide temperature range, with a 100 K temperature step, from 200 K to 2400 K and 200 K to 1400 K for the cubic and monoclinic phases of zirconia, respectively, and 200 K to 1400 K for zircon. The temperature dependence of the lattice parameters and the equilibrium atomic volumes show good agreement with available experimental data. Next, the phonon thermal conductivity is calculated by analysing the raw data of the heat current autocorrelation function. The results illustrate that the above-mentioned materials have quite low thermal conductivities that are dependent on temperature. It is also shown that the lattice thermal conductivity of the different phases of zirconia and zircon can be decomposed into three contributions due to the acoustic short-range, long-range phonon and optical phonons modes. Finally, the thermal conductivity results from this study are compared with previous experimental studies and very good agreement is found.

中文翻译：

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通过分子动力学模拟预测锆石的晶格热导率和氧化锆的立方相和单斜相

摘要 氧化锆（ZrO2）和锆石（ZrSiO4）在高温下具有较高的强度和稳定性，同时还具有显着的热性能，如较低的热导率。在目前的研究中，研究了锆石和氧化锆的两种多晶型物（立方相和单斜相）的声子热导率。为此，提出了使用经典原子间势和 Green-Kubo 形式主义的平衡分子动力学模拟。结果在很宽的温度范围内详细给出，温度步长为 100 K，氧化锆的立方相和单斜晶相分别为 200 K 至 2400 K 和 200 K 至 1400 K，锆石为 200 K 至 1400 K . 晶格参数和平衡原子体积的温度依赖性与可用的实验数据显示出良好的一致性。下一个，通过分析热流自相关函数的原始数据来计算声子热导率。结果表明，上述材料具有与温度相关的非常低的热导率。还表明，由于声学短程、长程声子和光学声子模式，氧化锆和锆石不同相的晶格热导率可以分解为三种贡献。最后，将本研究的热导率结果与之前的实验研究进行比较，发现非常一致。还表明，由于声学短程、长程声子和光学声子模式，氧化锆和锆石不同相的晶格热导率可以分解为三种贡献。最后，将本研究的热导率结果与之前的实验研究进行比较，发现非常一致。还表明，由于声学短程、长程声子和光学声子模式，氧化锆和锆石不同相的晶格热导率可以分解为三种贡献。最后，将本研究的热导率结果与之前的实验研究进行比较，发现非常一致。