A reverse Monte Carlo method for deriving optical constants of solids from reflection electron energy-loss spectroscopy spectra
A reverse Monte Carlo method for deriving optical constants of solids from reflection electron energy-loss spectroscopy spectra
复制标题
从反射电子能量损失光谱中推导固体光学常数的逆蒙特卡罗方法
DOI：
10.1063/1.4809544
复制
发表时间：
2013-06-07
影响因子：
3.2
通讯作者：
Ding, Z. J.
中科院分区：
文献类型：
--
作者：
Da, B.;Sun, Y.;Ding, Z. J.
开发了一种逆蒙特卡罗 (RMC) 方法，通过迭代蒙特卡罗 (MC) 模拟程序从测量的反射电子能量损失光谱 (REELS) 光谱中获取能量损失函数 (ELF) 和光学常数。该方法将模拟退火方法（即振荡器参数、表面和体激励权重因子以及带隙能量的马尔可夫链蒙特卡罗（MCMC）采样）与电子与固体相互作用的传统 MC 模拟相结合，作为该 RMC 方法中 MCMC 采样的单个步骤。为了检验该方法的可靠性，我们验证了介电函数的输出数据基本上独立于试验参数的初始值，这是MCMC方法的基本属性。 SiO2 在 8-90 eV 能量损失范围内推导的光学常数与其他可用数据非常一致，并且通过振荡器强度和和完美筛选和规则检查了相关体 ELF。我们的结果表明，即使初始试验参数范围很广，也可以通过 RMC 方法获得介电函数。因此，RMC 方法是通过 REELS 测量确定固体光学特性的通用且有效的方法。 (C) 2013 AIP 出版有限责任公司。
A reverse Monte Carlo (RMC) method is developed to obtain the energy loss function (ELF) and optical constants from a measured reflection electron energy-loss spectroscopy (REELS) spectrum by an iterative Monte Carlo (MC) simulation procedure. The method combines the simulated annealing method, i.e., a Markov chain Monte Carlo (MCMC) sampling of oscillator parameters, surface and bulk excitation weighting factors, and band gap energy, with a conventional MC simulation of electron interaction with solids, which acts as a single step of MCMC sampling in this RMC method. To examine the reliability of this method, we have verified that the output data of the dielectric function are essentially independent of the initial values of the trial parameters, which is a basic property of a MCMC method. The optical constants derived for SiO2 in the energy loss range of 8-90 eV are in good agreement with other available data, and relevant bulk ELFs are checked by oscillator strength-sum and perfect-screening-sum rules. Our results show that the dielectric function can be obtained by the RMC method even with a wide range of initial trial parameters. The RMC method is thus a general and effective method for determining the optical properties of solids from REELS measurements. (C) 2013 AIP Publishing LLC.