MatBaseX: Comprehensive Materials and X-ray Interaction Database for Photoelectron Spectroscopy Analysis
MatBaseX is a comprehensive database and analytical tool tailored for photoelectron spectroscopy (PES) analysis, emphasizing the study of materials and their X-ray interactions. It seamlessly integrates calculators and databases into one platform, providing functionalities such as a Materials Properties Database for managing data, tools for analysing X-ray Photoionization Energies, Cross-Sections, and X-ray Absorption and Scattering Factors. These features help users very quickly identify which core-levels give the most intensity at a given photon energy (via cross-section maximisation) or locate absorption edges for resonance spectroscopy. It also includes calculators for electron inelastic mean free path (IMFP) determination using eight different formalisms, as well as an XPS Sensitivity Factor Calculator to support precise, quantitative PES analysis.
Additional features include PES N-Layer Simulations, which utilizes the Beer-Lambert law to compute intensities for a user-defined heterostructure, and a PES Curve Fitting App that allows users to quickly load in experimental data (two-column text file containing binding energy and intensity values) and determine the best fit. By integrating all these advanced databases, calculators, and analytical tools, MatBaseX helps researchers streamline workflows and enhance the precision of their data analysis. Download MatBaseX today to explore its powerful capabilities!
- Download the MatBaseX repository.
- Open MATLAB and use Set Path in the Home tab to add the MatBaseX repository and all its sub-folders into its saved search paths.
- Make sure you also use Set Path to add the repository / folder that contains all of your data to be loaded in.
- Type 'MatBaseX' in the MATLAB Command Prompt to boot up the Main Menu App.
Or, simply download & install the standalone app via the executable file here!
(1) MatBase Main Menu: The main-menu that provides seamless navigation to all available applications. Accessible in MATLAB by typing 'MatBaseX' in the command prompt.
(2) Materials Database Editor: Effortlessly manage the Materials Properties Database with this intuitive and user-friendly app. There are currently 179 material entries, including data on elements, oxides, binary semiconductors, and ionic salts. New compound data can be easily added, with options to modify, delete, and export the properties of any element or compound. All changes can be made with confidence, keeping the database updated and persistent for all your future needs.
(3) Crystallography Viewer: View unit cells in both real and reciprocal space, calculate the Brillouin zone, and extract 2D slices for analysis. Conveniently access material parameters from the Materials Properties Database or manually enter data for materials not included in the database.
(4) X-Ray Photoionization Binding Energy & Cross-Section Database: Comprehensive element data is available for elements 1-98, derived from four distinct formalisms: Scofield (1973), Yeh & Lindau (1985), Trzhaskovskaya (2018), and Cant (2022). The app allows for the plotting of binding energy spectra, photoionization cross-sections, and photoionization asymmetry parameters. Users can easily identify the optimal core levels for probing by locating maximum cross-sections at specific photon energies. Additionally, binding energies and photoionization parameters can be conveniently saved or exported as text files.
(5) X-Ray Absorption Edge & Scattering Factor Database: Elements 1-92 is available, including all material entries composed of these elements. The app allows users to plot and calculate absorption edge spectra (from IXAS) and scattering factors (from Henke and NIST). Additionally, it supports calculations for photoelectric mass attenuation coefficients, refractive indices, critical angles, transmission, and reflectance. Absorption edges for resonance spectroscopy can be easily identified, and users have the option to save or export absorption edges or scattering factors as text files.
(6) Electron Inelastic Mean Free Path Calculator: Users have access to all material entries, and can also manually input data for materials not included in the database. The platform enables plotting and calculation of the Inelastic Mean Free Path (IMFP) using various formalisms, such as Universal, TPP-2M, Optical Data (NIST), S1, S2, S3, S4, and JTP methods. Additionally, it estimates standard deviation across these methods for uncertainty quantification. IMFP data can be plotted, exported, or saved for future reference.
(7) XPS Sensitivity Factor Calculator: The app seamlessly integrates databases for IMFP, photoionization cross-sections, and asymmetry parameters. Users can customize experimental geometry, photon polarization, and select preferred formalisms for IMFP and cross-section calculations. Core levels can be easily chosen to generate sensitivity factor plots against photon energy and emission angle with just one click, making it invaluable for precise and quantitative XPS analysis. All data can be saved and / or exported as text files for convenience. Indispensable for precise, quantitative XPS analysis.
(8) PES - N-Layer Simulations: The app provides access to all material entries, enabling users to design an N-layer heterostructure sample stack with uniform concentration and thickness. It also integrates the databases for IMFP, photoionization cross-sections, and asymmetry parameters. PES intensities can be precisely calculated using the Beer-Lambert law, adjusted for electron IMFP in alignment with experimental configurations. Users can visually represent variations in photon energy and emission angles. Models can be saved for future use, easily reloaded into the application, and exported as .txt files for external use.
(9) PES - Curve Fitting: Accurately peak fit your XPS/PES data. Construct initial models with various curve shapes (Gaussian, Lorentzian, Voigt, or Doniach-Sunjic). Manually define the binding energy, spin-orbit split components and branching ratios or type in the core-level of interest, and if it exists in the binding energy database, all these parameters will be loaded automatically. Subtract the background using Polynomial, Shirley, or Tougaard methods, and enter lower/upper bound estimates for fit parameters. Run optimization algorithms to achieve the best fit. Fits can be exported or saved, and reloaded into the application for future use. Simple and efficient to use for fast peak fitting and chemical shift identification.
MATLAB version: 2024b
MATLAB add-ons (not required, but recommended): Curve Fitting Toolbox, Global Optimization Toolbox, Image Processing Toolbox, Optimization Toolbox.
Dr. Procopios Constantinou,
Swiss Light Source (SLS),
Paul Scherrer Institute (PSI),
email: procopios.constantinou@psi.ch
I would like to thank Dr. Vladimir Strocov (PSI) for his guidance and feedback regarding the software.
Materials Properties Database
[1] Electronegativity, electron affinity, ionisation energies, temperatures and crystal structures
[2] Temperatures, crystal structures, unit cell parameters, electronic and magnetic properties
[3] Strehlow, W. H., and Earl L. Cook. "Compilation of energy band gaps in elemental and binary compound semiconductors and insulators." (1973): 163-200.
[4] Band-gap estimates, temperatures, crystal structures, unit cell parameters, electronic and magnetic properties
[5] Atomic weights of elements and compounds
Photoionization Energies, Cross-Sections & Asymmetry
Scofield Database (1973):
[6] Scofield, J. H. "Theoretical photoionization cross sections from 1 to 1500 keV"
Yeh & Lindau Database (1985):
[7] Yeh, J. J., and I. Lindau. "Atomic subshell photoionization cross sections and asymmetry parameters: 1⩽ Z⩽ 103." Atomic data and nuclear data tables 32.1 (1985): 1-155
Moulder Binding Energies Database (1993):
[8] Moulder, John F. et al. “Handbook of X-Ray Photoelectron Spectroscopy.” (1992).
Trzhaskovskaya Database (2018-2019):
[9] Trzhaskovskaya, M. B., and V. G. Yarzhemsky. "Dirac–Fock photoionization parameters for HAXPES applications." Atomic Data and Nuclear Data Tables 119 (2018): 99-174.
[10] Trzhaskovskaya, M. B., and V. G. Yarzhemsky. "Dirac–Fock photoionization parameters for HAXPES applications, Part II: Inner atomic shells." Atomic Data and Nuclear Data Tables 129 (2019): 101280
Cant Database (2018-2019):
[11] Cant, David JH, et al. "Quantification of hard X‐ray photoelectron spectroscopy: Calculating relative sensitivity factors for 1.5‐to 10‐keV photons in any instrument geometry." Surface and Interface Analysis 54.4 (2022): 442-454
X-Ray Absorption Edge & Scattering Factors Database Sources
Henke Database (1993):
[12] B. L. Henke, E. M. Gullikson, and J. C. Davis, Atomic Data and Nuclear Data Tables Vol. 54 No. 2 (July 1993)
NIST Database (2005):
[13] NIST Standard Reference Database 66, "Detailed Tabulation of Atomic Form Factors, Photoelectric Absorption and Scattering Cross Section, and Mass Attenuation Coefficients for Z = 1-92 from E = 1-10 eV to E = 0.4-1.0 MeV" (January 2005)
IXAS Database (2025):
[14] IXAS X-ray Data for the Elements
Inelastic Mean-Free Path (IMFP) Sources
Universal (1979):
[15] Seah, M. Pl, and W. A. Dench. "Quantitative electron spectroscopy of surfaces: A standard data base for electron inelastic mean free paths in solids." Surface and interface analysis 1.1 (1979): 2-11
TPP-2M Formalism (1994):
[16] Tanuma, Shigeo, Cedric J. Powell, and David R. Penn. "Calculations of electron inelastic mean free paths. V. Data for 14 organic compounds over the 50–2000 eV range." Surface and interface analysis 21.3 (1994): 165-176
[17] Tanuma, Shigeo, Cedric J. Powell, and David R. Penn. "Calculation of electron inelastic mean free paths (IMFPs) VII. Reliability of the TPP‐2M IMFP predictive equation." Surface and interface analysis 35.3 (2003): 268-275
[18] Seah, M. P. "An accurate and simple universal curve for the energy‐dependent electron inelastic mean free path." Surface and interface analysis 44.4 (2012): 497-503
[19] Tanuma, Shigeo, C. J. Powell, and D. R. Penn. "Calculations of electron inelastic mean free paths. IX. Data for 41 elemental solids over the 50 eV to 30 keV range." Surface and interface analysis 43.3 (2011): 689-713
NIST Electron IMFP Database (1999):
[20] NIST Standard Reference Database 71
S1 & S2 Formalism (2011):
[21] Seah, M. P. "An accurate and simple universal curve for the energy‐dependent electron inelastic mean free path." Surface and interface analysis 44.4 (2012): 497-503
S3 & S4 Formalism (2012):
[22] Seah, M. P. "Simple universal curve for the energy‐dependent electron attenuation length for all materials." Surface and interface analysis 44.10 (2012): 1353-1359
JTP Formalism (2023):
[23] Jablonski, Aleksander, Shigeo Tanuma, and Cedric J. Powell. "Calculations of electron inelastic mean free paths (IMFPs). XIV. Calculated IMFPs for LiF and Si3N4 and development of an improved predictive IMFP formula." Surface and Interface Analysis 55.8 (2023): 609-637
Useful PES Quantification Literature
[24] Hill, J. M., et al. "Properties of oxidized silicon as determined by angular-dependent X-ray photoelectron spectroscopy." Chemical Physics Letters 44.2 (1976): 225-231
[25] Walton, J., et al. "Film thickness measurement and contamination layer correction for quantitative XPS." Surface and Interface Analysis 48.3 (2016): 164-172
[26] Shard, Alexander G. "Practical guides for x-ray photoelectron spectroscopy: Quantitative XPS." Journal of Vacuum Science & Technology A 38.4 (2020)
Useful Websites for XPS Information & Application Notes
[27] NIST X-ray Photoelectron Spectroscopy Database
[28] Surface Science Western laboratories (XPS Reference Pages)
[29] XPS Information and Application Notes
[30] B. Vincent Crist: International XPS Database
[31] B. Vincent Crist: XPS Information and Application Notes
[32] A. Regoutz: Source of the Digitized Photoionization Parameters
This project is licensed under the GNU General Public License v3.0 - see the LICENSE.md file for details.
--PCC, April 2025