Extended Mermin Method for Calculating the Electron Inelastic Mean Free Path
Extended Mermin Method for Calculating the Electron Inelastic Mean Free Path
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计算电子非弹性平均自由程的扩展 Mermin 方法
DOI：
10.1103/physrevlett.113.063201
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发表时间：
2014-08-07
影响因子：
8.6
通讯作者：
Tanuma, S.
中科院分区：
文献类型：
--
作者：
Da, B.;Shinotsuka, H.;Tanuma, S.
提出了一种改进的方法，用于计算电子在固体中的非弹性平均自由程（IMFPs）的实验能量损失函数的基础上的Mermin介电函数。“扩展Mermin”方法采用了非限制数量的Mermin振荡器，并允许负振荡器不仅考虑电子跃迁，如传统方法中常见的，而且还考虑红外跃迁和内壳层电子激发。当扩展到无限动量转移时，只使用Mermin振子自然地保留了两个重要的求和规则。极好的协议之间的计算IMFPs铜和弹性峰电子能谱的实验测量。显着改善拟合IMFP来自分析的X射线吸收精细结构测量Cu和Mo说明的重要性，在低能量的IMFP计算中的红外跃迁的贡献。
We propose an improved method for calculating electron inelastic mean free paths (IMFPs) in solids from experimental energy-loss functions based on the Mermin dielectric function. The "extended Mermin" method employs a nonlimited number of Mermin oscillators and allows negative oscillators to take into account not only electronic transitions, as is common in the traditional approaches, but also infrared transitions and inner shell electron excitations. The use of only Mermin oscillators naturally preserves two important sum rules when extending to infinite momentum transfer. Excellent agreement is found between calculated IMFPs for Cu and experimental measurements from elastic peak electron spectroscopy. Notably improved fits to the IMFPs derived from analyses of x-ray absorption fine structure measurements for Cu and Mo illustrate the importance of the contribution of infrared transitions in IMFP calculations at low energies.