The use of the full Penn algorithm (FPA) for calculating the inelastic mean free path (IMFP) in materials with a band gap E_g was explained. Additionally, the details of applying relativistic corrections to both the FPA and the single pole approximation (SPA) by Penn for calculating the IMFP in high-energy regions exceeding such as 100 keVwere discussed. There are two factors regarding the effect of E_g on IMFP calculations. The first is that the minimum and maximum values of the electron energy loss change, and the second is how to express the momentum transfer that is altered due to the presence of E_g. For these aspects, the FPA-BABC method, developed based on the work by Boutboul et al. [ J. Appl. Phys. 79, 6714(1996)], and refined by Shinotsuka et al.[Surf. Interface Anal. 54, 534 (2022)] was explained. Regarding the application of relativistic corrections to FPA and SPA, it is shown that for energy regions below 500 keV, the corrections can be relatively easily incorporated by applying relativistic kinematic adjustments to electron motion. Furthermore, a comparative study was conducted on the IMFPs obtained from relativistic SPA and relativistic FPA-BABC across 45 inorganic compounds and 14 organic compounds in the energy range from 200 eV to 500 keV. The results indicated that, at around 200 keV, the relative differences between the SPA-IMFPs and FPA-BABC-IMFPs were on average below approximately 2% for inorganic compounds and below 1% for organic compounds. The maximum deviation between the two methods in the energy range of 200 eV to 500 keV was about 3%. From the above, it becomes clear that the relativistic SPA can be used to calculate the IMFP in the energy range of 200 eV- 500 keV even for materials with E_g.

View full abstract

In the XPS spectrum, peaks other than the photoelectron main peaks and Auger electron peaks are collectively called “satellite peaks”. Understanding the origin and examples of satellite peaks is important to distinguish the chemical state of each element and to understand the electronic structure. In this commentary, information on satellite peaks is arranged and introduced as a topic.

View full abstract

In recent years, advances in analysis software have made it possible to automatically perform data analysis for simple, single-spectrum analyses. This is crucial for ensuring the reproducibility and objectivity of data analysis. However, there is a growing concern that this automation may turn data analysis into a black box, leading to situations where analysis is conducted through unnatural processes without users even realizing it. This issue is also prevalent in the analysis of spectral data. In this article, we introduce a small part of the mathematical structure of spectral analysis within the framework of Bayesian statistics, with a particular focus on the design of the error function. Additionally, we also show that the Bayesian statistical framework naturally leads to integrated analysis of multiple spectra, as would be achieved by a skilled analyst.

View full abstract

We conducted laboratory-based HAXPES experiments with either a monochromatic Cr Kα or Ga Kα x-ray source to nondestructively perform chemical state analysis with bulk sensitivity, in comparison with conventional XPS using Mg Kα and Al Kα x-ray sources. To analyze the bulk-sensitive chemical states of silver and copper elements having a relatively small chemical shift in the Ag 3d_5/2 and Cu 2p_3/2 regions, we attempt to use Ag L₃M_4,5M_4,5 and Cu KL_2,3L_2,3 Auger electrons with a large inelastic mean free path (IMFP). In this paper, the Ag 3d_5/2 − Ag L₃M_4,5M_4,5 and Ag 2p_3/2 − Ag L₃M_4,5M_4,5 modified Auger parameters were measured by Cr Kα excitation for thirteen silver-containing materials: Ag, Ag_0.09P_0.1Cu_0.81, Ag_0.6Cu_0.4, Ag₂O, Ag₂O₂, Ag₂S, AgI, AgBr, AgCl, AgF, Ag₂CO₃, AgNO₃, and Ag₂SO₄. The Cu 2p_3/2 − Cu KL_2,3L_2,3 modified Auger parameter was also measured by Ga Kα excitation for five copper-containing materials: Cu, Cu_0.6Zn_0.4, Cu₂O, CuBr, and CuO. The Wagner plot of the silver and copper materials were drawn with the obtained modified Auger parameters. The results indicate that the approach demonstrated here was effective in identifying the chemical states of the surface oxide layers formed by melting and subsequent solidification of a silver brazing alloy (Ag_0.6Cu_0.4).

View full abstract

Tapes and films with various functions are our main products. It is important to understand the characteristics of the surface in contact with the adhesive. Therefore, our company focuses on surface analysis, such as Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS). However, its data is very complex and difficult to analyze. In this presentation, we report the application of principal component analysis (PCA), multivariate curve resolution (MCR) and autoencoder (AE) to the following TOF-SIMS data. Ⅰ: Analysis of oil content on coating film surface Ⅱ: Analysis of residue after tape peeling As a result, the important features of each component in the samples were extracted by these methods, and then the molecular structures were indicated．

View full abstract