A review of directional Auger (DAES) and directional elastic peak electron spectroscopy (DEPES) for investigations of the short range order within a near-surface region, similar to XPD, is presented. The application of these techniques requires nothing more than a retarding field analyser (RFA), commonly applied for the observation of low energy electron diffraction (LEED) patterns and Auger electron spectroscopy (AES) measurements, for in depth structural investigations associated with the short range order within a near-surface region. The physical principles, experimental set-up, as well as examples of experimental and theoretical results, the latter obtained with the use of single scattering cluster (SSC) and multiple scattering (MS) calculations adopted for primary electron plane wave, are shown. The scattering geometry and details concerning the scattering events of primary electrons in crystalline solids described by SSC and MS approximations are presented. Furthermore, some issues related to computation parameters such as: maximal scattering order, the maximum radius around the emitter, the number of cluster layers, and the averaging range considered in the calculations are also addressed. The presentation of the data obtained for clean and covered substrates in the form of polar profiles and stereographic intensity distributions enables the straightforward identification of the crystalline structure within the first few sample layers. The data presented in the form of anisotropy maps enable the identification of interatomic axes formed between substrate and adsorbate atoms at the interface. The contribution of different sample layers to the final DEPES signal is discussed. The comparison of DAES results with those obtained by means of x-ray photoelectron diffraction (XPD) is also presented. The qualitative and quantitative data analysis, the latter achieved by the comparison of experimental data with theoretical results by means of an R-factor analysis, is shown. The application of DAES and DEPES enables the characterization of the crystalline structure of adsorption systems from one monolayer (1 ML) up to thicknesses of the adsorbate limited by the inelastic mean free path of the registered electrons. Exemplary results are presented for adsorption systems, where the adsorbate and the substrate crystallize in the same (Ag/Cu, Pt/Cu, Cu/Pt) and in different (Cu/Ru) structures. The influence of the large unit cell of graphene formed on Ru(0001) on measured DEPES intensities is also shown. The detailed analysis of these results enables an identification of the short range order of atoms within the near-surface region, of adsorbate domains exhibiting different orientation with respect to the crystalline substrate, the determination of the domain populations, the relaxation and termination of the surface, the specific adsorption sites of adsorbed atoms, as well as the positions of atoms within a unit cell and their bond lengths (e.g. $O/Ru\left(10\overline{1}0\right)$).

介绍了方向性俄歇（DAES）和方向性弹性峰电子能谱（DEPES）的综述，以研究类似于XPD的近表面区域内的短程有序。这些技术的应用仅需要延迟场分析仪（RFA），通常用于观察低能电子衍射（LEED）模式和俄歇电子能谱（AES）测量，用于与短程相关的深度结构研究在近地表区域内有序。显示了物理原理，实验设置以及实验和理论结果的示例，后者是通过使用单次散射簇（SSC）和多次散射（MS）计算获得的，用于主电子平面波。给出了散射几何结构和有关SSC和MS近似描述的晶体固体中一次电子的散射事件的详细信息。此外，还解决了一些与计算参数有关的问题，例如：最大散射阶数，发射器周围的最大半径，簇层数以及计算中考虑的平均范围。以极性分布和立体强度分布的形式呈现清洁的和覆盖的基材所获得的数据，可以直接识别前几个样品层中的晶体结构。以各向异性图的形式呈现的数据使得能够识别在界面处的底物和吸附原子之间形成的原子间轴。讨论了不同样本层对最终DEPES信号的贡献。还介绍了DAES结果与通过X射线光电子衍射（XPD）获得的结果的比较。显示了定性和定量数据分析，后者是通过R因子分析将实验数据与理论结果进行比较而实现的。DAES和DEPES的应用可以表征吸附系统的晶体结构，从一个单层（1 ML）到受配准电子的非弹性平均自由程限制的被吸附物厚度。给出了对于吸附系统的示例性结果，其中被吸附物和基质在相同的（Ag / Cu，Pt / Cu，Cu / Pt）和不同的（Cu / Ru）结构中结晶。还显示了在Ru（0001）上形成的石墨烯大晶胞对测得的DEPES强度的影响。对这些结果的详细分析使得能够识别在近表面区域内的原子的短程顺序，相对于晶体基质表现出不同取向的被吸附结构域，确定结构域总体，表面的弛豫和终止，被吸附原子的特定吸附位点以及晶胞内原子的位置及其键长（例如$Ø/\mathrm{[R}ü（10\overline{\mathrm{1个}}0）$）。