论文标题
在中等温度下金属的热导率和洛伦兹的比率：第一原理分析
Thermal conductivity and Lorenz ratio of metals at intermediate temperature: a first-principles analysis
论文作者
论文摘要
电子和语音导热率与金属的热传导有关，而Wiedemann-Franz定律通常用于单独预测它们。但是，在中等温度下，Wiedemann-Franz定律被证明是无效的。在这里，为了获得金属的准确导热率和洛伦兹的比率，动量松弛时间用于电子导热率的电导率和能量弛豫时间。模式级第一原理计算是在两个代表性金属铜和铝上进行的。结果表明，该方法可以正确预测6至300 k的电运输系数。此外，在本方案中观察到异常的洛伦兹比率，这与Sommerfeld值显着偏离。计算方案可以扩展到其他金属系统，并且在更好地理解金属的电子动力学和传输特性方面非常有价值。
Electronic and phononic thermal conductivity are involved in the thermal conduction for metals and Wiedemann-Franz law is usually employed to predict them separately. However, Wiedemann-Franz law is shown to be invalid at intermediate temperatures. Here, to obtain the accurate thermal conductivity and Lorenz ratio for metals, the momentum relaxation time is used for electrical conductivity and energy relaxation time for electronic thermal conductivity. The mode-level first-principles calculation is conducted on two representative metals copper and aluminum. It is shown that the method can correctly predict electrical transport coefficients from 6 to 300 K. Also, the anomalous Lorenz ratio is observed within the present scheme, which has significant departure from the Sommerfeld value. The calculation scheme can be expanded to other metallic systems and is valuable in a better understanding of the electron dynamics and transport properties of metals.
