RuO2和IrO2的電子傳輸性質

Abstract

二氧化釕(RuO2)和二氧化銥(IrO2)在高溫下具有良好的導電性和穩定性。我們用第一原理去研究不同口徑下 和 的電子傳輸性質，在計算的方法裡，我們運用密度泛函理論(Density Functional theory)去最佳化 和 的結構和用局部密度近似法(Local Density approximation)去近似。經過計算結果我們可以得到不同口徑下 和 奈米線的聲子色散關係而且發現聲速和Debye溫度隨著材料的尺寸增加而增加。藉著Bloch-Gruneisen方程式可以知道在低溫下，來自於電子聲子交互作用的電阻率隨著溫度五次方成正比而且在同樣溫度下，聲速和Debye溫度導致電阻率隨著奈米線的半徑增加而增加。

RuO2 and IrO2 are the inviting electrical contact materials which exhibit the metallic conductivity properties at room temperatures. They crystallize in the rutile structures and display good thermal stability at high temperatures. We study the size effects of the transport properties of RuO2 and IrO2 nanowires using first-principles approaches. The relaxed structures of RuO2 and IrO2 bulk and nanowires are obtained based on the density functional theory. By using the force tensor we calculate the phonon dispersion relation of the RuO2 and IrO2 nanowires with different diameters. We observe that the sound velocities and the Debye temperatures display size effects. According to the Bloch-Gruneisen model within Matthiessen’s rule, the resistivity varies as at low temperatures due to electron-phonon interactions. At the same temperatures, the size effects of the sound velocity and the Debye temperatures lead to the increase of the resistivity as the diameters of the nanowires increase.