Reflectivity of metals at high temperatures
Reflectivity of metals at high temperatures
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DOI：
10.1109/jqe.1972.1077175
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发表时间：
1972-05
影响因子：
2.5
通讯作者：
K. Ujihara
中科院分区：
文献类型：
--
作者：
K. Ujihara
根据Drude理论和电子-声子碰撞理论，讨论了金属在高温下的反射率和其它光学常数。电子-声子碰撞频率通过声子布居的温度依赖性而依赖于温度。碰撞频率的温度依赖性决定了金属光学性质的温度依赖性。考虑了介电常数和复折射率随温度的真实的和虚部的变化。给出了光学常数温度系数的一般表达式。反射率随温度的升高而降低。数值计算进行了几种金属在几个波长和温度从室温到他们的熔化温度。结果以图表形式给出。反射率曲线表明，对于在室温下反射率较低的金属，反射率温度系数的绝对值较大。室温下的反射率计算值与手册数据符合较好。然而，计算的反射率银在其熔点是不符合报道的实验数据（目前唯一可用的数据），尽管我们的结果和实验之间的定性协议。对这种差异的可能解释进行了简要的讨论。
The reflectivity and other optical constants of metals at high temperatures are discussed on the basis of the Drude theory and the theory of electron‐phonon collision. The electron‐phonon collision frequency is dependent on the temperature through the temperature dependence of the phonon population. The temperature dependence of the collision frequency determines that of optical properties of metals. Variations of the real and the imaginary parts of the dielectric constant and of the complex refractive index with temperature are considered. General expressions for the temperature coefficients of the optical constants are given. The reflectivity is shown to decrease with increasing temperature. Numerical calculations were carried out for several metals at a few wavelengths and at temperatures from room temperature to their melting temperatures. The results are given in graphs and in a table. Curves for the reflectivity show that the absolute value of the temperature coefficient of the reflectivity is greater for a metal having a lower reflectivity at room temperature. Calculated values of the reflectivity at room temperature are in reasonable agreement with handbook data. However, the calculated reflectivity for silver at its melting point is not coincident with the reported experimental data (the only data available at present), in spite of the qualitative agreement between our results and the experiment. A brief discussion on possible explanations of the discrepancy is made.