# A Bibliographic Database of X-Ray Emissions as a Function of the Chemical State of the Emitting Element

Philippe Jonnard

► To cite this version:

Philippe Jonnard. A Bibliographic Database of X-Ray Emissions as a Function of the Chemical State of the Emitting Element. X-Ray Spectrometry, 2025, 55 (1), pp.176-183. 10.1002/xrs.70033. hal-05408336

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Submitted on 10 Dec 2025

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Distributed under a Creative Commons Attribution 4.0 International License
A bibliographic database of x-ray emissions
as a function of the chemical state of the
emitting element

Philippe JONNARD

Sorbonne Université, CNRS, Laboratoire de Chimie Physique - Matière et Rayonnement, LCPMR, F-75005 Paris, France

philippe.jonnard@sorbonne-universite.fr

Abstract

The wavelengths or energies of the x-ray characteristic emission lines of the elements can be found in some databases. However, it is well-known that the energy of the maximum of an atomic line or an emission band can vary with the chemical state of the emitting element. Moreover, the energy of the maximum is just an interesting characteristic; the shape of the emission can also give information regarding the chemical state. This is why, I found worthwhile to compile in a bibliographic database the studied emission lines as a function of the chemical state of the emitting element. Articles from 1922 up to the present are introducing atomic lines, emission bands, satellites emissions from almost all the natural elements of the periodic table. The database will be useful to complete other spectroscopic characterization by x-ray photoelectron, x-ray absorption, electron energy loss spectroscopies, ... It will be helpful to prepare x-ray emission experiments, to check in an elemental quantification process by electron probe microanalysis if the intensity should be measured as the peak height or integrated intensity, to compare and validate simulated spectra as obtained by the density function theory, ... The database is available from the author in a pdf format.

Keywords

X-ray emission spectroscopy; chemical state; spectral resolution, bibliography, database
Introduction

Since the development of x-ray emission spectroscopy (XES) in the 1910’s, some tables of
wavelengths or energies of x-ray emission lines have been published in articles, books and on websites;
see references [1–12] for examples. Most of these databases consider only the most intense x-ray
emissions and give the spectra or photon energies for the elements in their pure form. However, it is
well-known that x-ray emissions can be sensitive to the chemical state of the emitting element. This is
particularly true for emission bands, originating from electron transitions taking place from the valence
band. In this case, the shape of an emission band describes the local (for a given element) and partial
(for a given symmetry of the state) density of states of the material [13–15] and so can change
drastically depending on the chemical environment of the emitting element.

To illustrate this last point, Figure 1 presents the Al Kβ emission from different aluminium
compounds: Al metal, γ-Al₂O₃, cubic AlN and Al₄C₃. This emission originates from the 3p-1s electron
transition and because the 3p electrons of aluminium are located in the valence band, the emission
band is very sensitive to the chemical state of the aluminium atom. Spectra were obtained with a high-
resolution crystal-bent x-ray spectrometer [16,17]. It is clearly observed that the position of the main
and secondary maxima as well as the width and shape change with the chemical state of the emitting
aluminium. The spectrum of the metal is characterized by the sudden drop in intensity at the top of
the emission band, 1559.4 eV, marking the position of the Fermi level. The secondary maximum of the
compounds shifts toward lower photon energies, or higher binding energies, when going from carbon
to oxygen, that is to say when the electronegativity of the ligand is increasing. It is possible to continue
the series with fluorine, with the AlF₃ spectrum which can be found in the bibliographic database [18].
From the series, it is expected that the spectrum of AlB₂ not found in the literature, would present its
secondary maximum around 1551 eV, very close to the main peak.

<figure><img src="image_2.png" /><figcaption>Figure 1: Al Kβ emission band of Al metal, γ-Al₂O₃, cubic AlN and Al₄C₃. The curves are normalized to their maximum. The vertical bars mark the position of the main and secondary maxima of AlF₃ indicated in Ref.[18].</figcaption></figure>

Since the 1920’s, thousands of articles presenting spectra obtained on numerous materials
have been published. Some authors studied the particular line of an element in a series of materials or
considered the effect of oxidation, nitridation or ligands on the shape and energy of valence bands;
this kind of studies also exist for satellites. However, there is no comprehensive study encompassing
all the possible chemical states and possible x-ray emissions of an element. This is why I thought
interesting to collect the different works reporting x-ray emission spectra of emitting elements in
various compounds and materials. Moreover, nowadays XES is not restricted to synchrotron beamlines or dedicated laboratories. Some commercial high-resolution XES spectrometers available for scanning electron microscopes, electron microprobes or x-ray fluorescence apparatus, are operated by users not expert in XES. Relying on a database and having a look to previously published spectra will guide the non-expert user and can diminish the risk of reporting erroneous results [19].

I decide to present all the available articles, and be as exhaustive as possible, without applying a critical selection as spectroscopy works are done upon different excitations means (electrons, photons, particles) and with different spectrometers equipped with crystals (for hard and soft x-rays, photon energy higher than 500 eV), periodic multilayers (for soft x-rays, $150 < E < 750$ eV) or gratings (for the ultra-soft and soft x-rays, $40 < E < 750$ eV). These wavelength dispersive spectrometers (WDS) lead to different spectral resolutions, sufficiently good so that the difference in the shapes or positions of the emissions as a function of the chemical states can be observed. This is why works resulting from energy dispersive spectrometers (EDS) operating with Ge, Si(Li) or silicon drift detectors, leading to poor spectral power with respect to WDS, are not presented. Works obtained with bolometers, which are EDS, are included because this kind of device generally gives a good spectral resolution, of the order of the eV, sensitive enough in some cases to observe some chemical effects.

Most of the presented materials are in the solid form but there are a few occurrences of materials in the liquid phase (water for example) or in the gas phase ($CO_2$ for example). The considered elements can be in bulk materials, in thin films, but also as impurities, dopants or adsorbates. The selected spectra were obtained following electron (XES, soft XES, electron probe microanalysis), photon (x-ray fluorescence) or particle (particle-induced x-ray emission) ionization. The spectra of highly ionized atoms, such as those occurring in plasmas or upon ionization by fast ions, are not selected for the database. Resonant inelastic x-ray spectrometry works presenting figures only as a function of the incident photon energy or as a function of the energy loss are not considered.

In the selected articles, data can be presented in different forms. Most of the recent papers publish spectra as figures, or display in tables the chemical shifts of the emissions. For older papers it can be that data are presented only in tables and in the case of the oldest ones, spectra can even be presented as reproductions of x-ray films. Most of the data come from journals of physics, chemistry, materials science, instrumentation. Most of the references point to articles published in English, but some articles, among the oldest ones, were also published in French and German. There are also a few citations of papers published in Russian, Japanese and Chinese languages. Very probably, some of the literature written in these languages has been overlooked. Finally, let us note that a spectra database has already been established, but restricted to the soft x-ray range spectra obtained on JEOL spectrometers [20,21]. For the same range a database website exists, created and maintained by the CSIRO in Australia [22].

## Description of the database

At the present time the database is a simple text file without sophisticated tool to browse the numerous entries. So, the best way to perform a bibliographic research is to look all the references regarding a particular emission or to look for all the results regarding a particular material. In parallel to this file, the references of the database are introduced in the Zotero bibliographic software [23]. This will help in the future to establish a real database, where author, title, journal name, year, DOI, ..., could also be used and combined to perform a database query.

The database comprises about 6000 bibliographic references and more than 41000 entries. The references do not cover the range of theoretical determination of emission energies, nor
astronomy, plasma science, cultural heritage and health science journals. However, if a high-resolution
experimental spectrum is presented in an article of these scientific domains, the corresponding
reference is added. The database is divided in three main parts: the list of references sorted by
alphabetic order of the elements; the list of journals; the list of compounds.

List of references

All the elements from lithium (Z=3) to californium (Z=98) are present in this list, except technetium (Z=43), astatine (Z=85), radon (Z=86), francium (Z=87) and actinium (Z=89). It is interesting to note that these absent elements are among the latest discovered natural elements and are only present in Earth in minute amounts [24]. The alphabetic order of the atomic symbols of the elements is used.

For each element, the different existing atomic lines or emission bands are introduced. They
are given from the K series (electron recombination toward the 1s level), to the L, M, N and also O
series for some of the heaviest elements. In one series, the lines occur from the most intense one to
the less intense one, that is to say, first α, then β, γ, ... emissions and then subdivided from 1 to 10 or
more. For faint lines which do not have a Siegbahn name [25], the IUPAC notation is followed, i.e. two
levels involved in the electron transition are given. When some emissions are close they can be given
together; this is the case for the Lα and Lβ emissions from 3d elements. Finally, some satellites are also
considered; hyper-satellites are indicated if work exists. To give an example, the different L emissions
of silver in the database are Lα<sub>1,2</sub>, Lβ<sub>1</sub>, Lβ<sub>2,15</sub>, Lβ<sub>3</sub>, Lβ<sub>4</sub>, Lβ<sub>6</sub>, Lβ<sub>9</sub>, Lβ<sub>10</sub>, Lγ<sub>1</sub>, Lγ<sub>2,3</sub>, Lγ<sub>5</sub>, Llη, Lα satellites, L
radiative Auger satellites.

For each emission there are five columns:

1. The first column gives the IUPAC or Siegbahn name of the emission;

2. The second column gives the name of the materials; it starts from the pure element, then all the materials which names begin by the element and finally the materials sorted by symbol of their element or of their name if there is no chemical formula. As an example, for the Al Kα<sub>1,2</sub> emission this gives (excerpt from 229 entries): Al, AlAs, AlAu, Al<sub>2</sub>Au, Al<sub>x</sub>Au<sub>1-x</sub>, AlB<sub>12</sub>, Al<sub>4</sub>C<sub>3</sub>, ..., Al<sub>2</sub>Te<sub>3</sub>, AlV<sub>2</sub>O<sub>4</sub>, albite, andalusite, (B<sub>2</sub>O<sub>3</sub>)(Al<sub>2</sub>O<sub>3</sub>)(CaO), Be<sub>3</sub>Al<sub>2</sub>Si<sub>6</sub>O<sub>18</sub> beryl, ..., TA6V, topaz, Y<sub>3</sub>Al<sub>5</sub>O<sub>12</sub> YAG, zeolith. Al<sub>x</sub>Au<sub>1-x</sub> is an alloy. The details about materials without well-known name, TA6V for example, or of minerals, albite for example, can be found in the list of compounds; for some old papers, it is sometimes difficult to identify which compound is presented in the cited article; in this case the occurrence is introduces as the pure element;

3. The third column gives the name of the first author of the publication;

4. The fourth column indicates the bibliographic reference with the name of the journal, conference, synchrotron activity report, or book given in an abbreviated way, the volume number if any, the number of the first page and the year; the details about journals, books and conferences can be found in the journal list; some PhD, mainly from France, are also used; when more than one reference exists for a given material, the entries are introduced in chronological order;

5. The fifth and last column is the DOI numbers of the bibliographic records; some Russian journals do not have DOI and in this case I indicate the URL of the article if any; for some old references this column is obviously empty; for some old books the ISBN numbers are given; in some particular cases a call to the journal list is indicated.

Some references, mainly Russian, give a lot of spectra of organic compounds. As it is difficult to order
the name and formula of organic compounds, the number of compounds considered in the cited
references is simply indicated (see the example below).
## List of journals

A lot of journal names used in the reference list are only indicated by their acronyms, for example ARI for the Applied Radiation and Isotopes journal. In the list of journals, the name of the journals is given in their abbreviated form, for example Appl. Rad. Isot. for Applied Radiation and Isotopes. In this list are also added:

* The abbreviated names of books used in the reference list; the full title is given together with its publication year and its editors; if the book is not too old, its DOI is indicated or by default the ISBN number, if any;

* The abbreviated name of conferences used in the reference list; if they are not too old, the website of the conference or of their proceedings is indicated; the editors and year are given;

* For some reviews not having a DOI, American Mineralogist of certain years for example, the URL address of some articles, too long to be introduced in the reference list, is given.

## List of compounds

A little less than 600 compounds, minerals or materials are introduced. These are the compounds which names are too long to be given in the list of references, or minerals which composition is too long or complicated, or even materials without definite composition. This list is sorted by alphabetic order and divided into four columns;

1. The name of the compound used in the reference list; this is the name used by the cited reference;

2. The full name of the compound;

3. The raw or developed chemical formula of the compound;

4. For some chemical compounds, a scheme of the molecule.

Possibly, for some compounds, another widely used name can be added.

## Examples

As a first example of the list of references, I put below a short extract of the records regarding silicon which is one of the elements having the largest number of entries. In the database it is 91 pages long (2901 lines) showing the importance and interest for this element. In the emission names below, "HS" means hyper-satellite and "RAE" radiative Auger effect.
<table>
  <tbody>
    <tr>
      <td rowspan="2">Si Kα1,2</td>
      <td rowspan="2">Si</td>
      <td>H. Takahara</td>
      <td>Rigaku Journal 38, 13 (2022)</td>
      <td>See List of journals</td>
    </tr>
    <tr>
      <td>Y. Ménesguen</td>
      <td>Rad. Phys. Chem. 194, 110048 (2022)</td>
      <td>10.1016/j.radphyschem.2022.110048</td>
    </tr>
    <tr>
      <td rowspan="10">Si4Al2O10(OH)2</td>
      <td rowspan="10">SiC</td>
      <td>X. Llovet</td>
      <td>Prog. Mat. Sci. 116, 100673 (2021)</td>
      <td>10.1016/j.pmatsci.2020.100673</td>
    </tr>
    <tr>
      <td>G.B. Deodhar</td>
      <td>PRSL A131, 633 (1931)</td>
      <td>https://www.jstor.org/stable/95630</td>
    </tr>
    <tr>
      <td>E. Bäcklin</td>
      <td>Z. Physik 38, 215 (1926)</td>
      <td>10.1007/BF01399110</td>
    </tr>
    <tr>
      <td>E. Bäcklin</td>
      <td>Z. Phys. 33, 547 (1925)</td>
      <td>10.1007/BF01328334</td>
    </tr>
    <tr>
      <td>B. Pitault</td>
      <td>CPL 81, 123 (1981)</td>
      <td>10.1016/0009-2614(81)85341-9</td>
    </tr>
    <tr>
      <td>H. Takahara</td>
      <td>Rigaku Journal 38, 13 (2022)</td>
      <td>See List of journals</td>
    </tr>
    <tr>
      <td>H. Hayashi</td>
      <td>Encyclopedia Anal. Sci. 1 (2014)</td>
      <td>10.1002/9780470027318.a9389</td>
    </tr>
    <tr>
      <td>S.G. Shevchenko</td>
      <td>JSC 23, 360 (1982)</td>
      <td>10.1007/BF00753471</td>
    </tr>
    <tr>
      <td>H. Takahara</td>
      <td>Rigaku Journal 38, 13 (2022)</td>
      <td>See List of journals</td>
    </tr>
    <tr>
      <td>H. Hayashi</td>
      <td>Encyclopedia Anal. Sci. 1 (2014)</td>
      <td>10.1002/9780470027318.a9389</td>
    </tr>
    <tr>
      <td>a-SiSn</td>
      <td>I. Ardelean</td>
      <td>PhD Univ. Paris 6 (1989)</td>
      <td></td>
    </tr>
    <tr>
      <td>a-Si1-xSnx</td>
      <td>I. Ardelean</td>
      <td>PhD Univ. Paris 6 (1989)</td>
      <td></td>
    </tr>
    <tr>
      <td rowspan="4">20 organic compounds<br/>[Al(f,OH)2]2SiO4 topaz</td>
      <td rowspan="4">SiCl4</td>
      <td>S.G. Shevchenko</td>
      <td>Doklady Akad. NAUK SSSR 264, 373 (1982)</td>
      <td></td>
    </tr>
    <tr>
      <td>W. Nefedow</td>
      <td>PSS B2, 904 (1962)</td>
      <td>10.1002/pssb.19620020709</td>
    </tr>
    <tr>
      <td>AlxRe</td>
      <td>Phil. Mag. 94, 1711 (2014)</td>
      <td>10.1080/14786435.2014.894648</td>
    </tr>
    <tr>
      <td>ZrSi2</td>
      <td>J. Hoszowska</td>
      <td>J. Phys. B33, 3165 (2000)</td>
      <td>10.1088/0953-4075/33/17/301</td>
    </tr>
    <tr>
      <td>ZrSiO4</td>
      <td>W. Nefedow</td>
      <td>PSS B2, 904 (1962)</td>
      <td>10.1002/pssb.19620020709</td>
    </tr>
    <tr>
      <td rowspan="2">Si Kα'</td>
      <td rowspan="2">Si</td>
      <td>Y. Ménesguen</td>
      <td>Rad. Phys. Chem. 194, 110048 (2022)</td>
      <td>10.1016/j.radphyschem.2022.110048</td>
    </tr>
    <tr>
      <td>M. Kavcic</td>
      <td>IJ-PIXE 24, 205 (2015)</td>
      <td>10.1142/S0129083514400130</td>
    </tr>
    <tr>
      <td rowspan="2">Si Kα3,4</td>
      <td rowspan="2">Si</td>
      <td>H. Takahara</td>
      <td>Rigaku Journal 38, 13 (2022)</td>
      <td>See List of journals</td>
    </tr>
    <tr>
      <td>Y. Ménesguen</td>
      <td>Rad. Phys. Chem. 194, 110048 (2022)</td>
      <td>10.1016/j.radphyschem.2022.110048</td>
    </tr>
    <tr>
      <td rowspan="2">Si Kαn</td>
      <td rowspan="2">Si</td>
      <td>Y. Ménesguen</td>
      <td>Rad. Phys. Chem. 194, 110048 (2022)</td>
      <td>10.1016/j.radphyschem.2022.110048</td>
    </tr>
    <tr>
      <td>S.P. Limandri</td>
      <td>PRA 82, 032505 (2010)</td>
      <td>10.1103/PhysRevA.82.032505</td>
    </tr>
    <tr>
      <td rowspan="2">Si Kα HS</td>
      <td rowspan="2">Si</td>
      <td>J. Hosowska</td>
      <td>JESRP 188, 62 (2013)</td>
      <td>10.1016/j.elspec.2012.09.001</td>
    </tr>
    <tr>
      <td>J. Hosowska</td>
      <td>PRL 107, 053001 (2011)</td>
      <td>10.1103/PhysRevLett.107.053001</td>
    </tr>
    <tr>
      <td rowspan="3">Si Kβ</td>
      <td rowspan="3">Si</td>
      <td>H. Takahara</td>
      <td>Rigaku Journal 38, 13 (2022)</td>
      <td>See List of journals</td>
    </tr>
    <tr>
      <td>D.F. Anagnostopoulos</td>
      <td>Spectrochim. Acta B148, 83 (2018)</td>
      <td>10.1016/j.sab.2018.06.004</td>
    </tr>
    <tr>
      <td>E. Bäcklin</td>
      <td>Z. Physik 38, 215 (1926)</td>
      <td>10.1007/BF01399110</td>
    </tr>
    <tr>
      <td rowspan="2">Si Kβ sat</td>
      <td rowspan="2">Si</td>
      <td>J. Hosowska</td>
      <td>JESRP 188, 62 (2013)</td>
      <td>10.1016/j.elspec.2012.09.001</td>
    </tr>
    <tr>
      <td>S.P. Limandri</td>
      <td>PRA 81, 012504 (2010)</td>
      <td>10.1103/PhysRevA.81.012504</td>
    </tr>
    <tr>
      <td rowspan="2">Si K RAE</td>
      <td rowspan="2">Si</td>
      <td>J. Kawai</td>
      <td>XRSCSA (2023)</td>
      <td>10.1007/978-981-19-7361-1</td>
    </tr>
    <tr>
      <td>K. Hassebi</td>
      <td>XRS 54, 76 (2025)</td>
      <td>10.1002/xrs.3427</td>
    </tr>
    <tr>
      <td rowspan="3">Si L2,3</td>
      <td rowspan="3">Si</td>
      <td>Y. Domi</td>
      <td>Chem. Commun. 60, 12986 (2024)</td>
      <td>10.1039/D4CC04134H</td>
    </tr>
    <tr>
      <td>H.W.B. Skinner</td>
      <td>PTRSL A239, 95 (1940)</td>
      <td>10.1098/rsta.1940.0009</td>
    </tr>
    <tr>
      <td>H.W.B. Skinner</td>
      <td>Rep. Prog. Phys. 5, 257 (1938)</td>
      <td>10.1088/0034-4885/5/1/323</td>
    </tr>
    <tr>
      <td rowspan="2">SiC</td>
      <td rowspan="2">Si</td>
      <td>H. Chen</td>
      <td>Materialia 21, 101369 (2022)</td>
      <td>10.1016/j.mtla.2022.101369</td>
    </tr>
    <tr>
      <td>M. Terauchi</td>
      <td>JEOL handbook (2021)</td>
      <td>https://www.jeol.com/download soft x-ray.php</td>
    </tr>
    <tr>
      <td rowspan="3">Si/ZnO<br/>activated carbon / Si</td>
      <td rowspan="3">AlMgSi</td>
      <td>M. Bär</td>
      <td>APL 97, 072105 (2010)</td>
      <td>10.1063/1.3462316</td>
    </tr>
    <tr>
      <td>V.M. Gun'ko</td>
      <td>ASS 258, 1115 (2011)</td>
      <td>10.1016/j.apsusc.2011.09.047</td>
    </tr>
    <tr>
      <td>A.S. Shulakov</td>
      <td>JESRP 62, 351 (1993)</td>
      <td>10.1016/0368-2048(93)85004-5</td>
    </tr>
    <tr>
      <td rowspan="2">Si L2,3 sat</td>
      <td rowspan="2">Si</td>
      <td>C. Beyreuther</td>
      <td>Phys. Fenn. 951, 168 (1974)</td>
      <td></td>
    </tr>
    <tr>
      <td>T. Käämbre</td>
      <td>MLAR8, 240 (2008)</td>
      <td></td>
    </tr>
    <tr>
      <td rowspan="2">Si L1L2,3</td>
      <td rowspan="2">Si</td>
      <td>R.D. Carson</td>
      <td>PRL 59, 319 (1987)</td>
      <td>10.1103/PhysRevLett.59.319</td>
    </tr>
    <tr>
      <td>R.S. Crisp</td>
      <td>J. Phys. Colloq. 48, C9-633 (1987)</td>
      <td>10.1051/jphyscol:19879107</td>
    </tr>
  </tbody>
</table>

The second example present the full list of references of a single element, caesium in this case, for which the number of published spectra is very limited; there is less than 40 lines. Such kind of general view on a poorly studied element could give information on the future emissions and compounds of this element which should be worth studied.
<table><thead><tr><th colspan="2">Cs - Caesium</th><th></th><th></th></tr></thead><tbody><tr><td>Cs K</td><td>133Ba</td><td>M. Rodriges</td><td>XRS 41, 64 (2012)</td><td>10.1002/xrs.2363</td></tr><tr><td>Cs Kα1,2</td><td>Cs</td><td>M.I. Marques</td><td>J. Phys. Colloq. 48, C9-601 (1987)</td><td>10.1051/jphyscol:1987999</td></tr><tr><td rowspan="2">Cs L</td><td>Cs</td><td>B.L. Doyle</td><td>PRA 19, 1433 (1979)</td><td>10.1103/PhysRevA.19.1433</td></tr><tr><td>CsBr</td><td>V. Sharma</td><td>PRA 78, 012507 (2008)</td><td>10.1103/PhysRevA.78.012507</td></tr><tr><td>Cs L sat</td><td>Cs(?)</td><td>G.B. Deodhar</td><td>J. Phys. B5, 710 (1972)</td><td>10.1088/0022-3700/5/3/037</td></tr><tr><td>Cs M2N1</td><td>CsCl</td><td>J. Dellith</td><td>Microchim. Acta 145, 25 (2004)</td><td>10.1007/s00604-003-0122-1</td></tr><tr><td>Cs M2N4</td><td>CsCl</td><td>J. Dellith</td><td>Microchim. Acta 145, 25 (2004)</td><td>10.1007/s00604-003-0122-1</td></tr><tr><td>Cs M3N1</td><td>CsCl</td><td>J. Dellith<br>F.D. Davidson</td><td>Microchim. Acta 145, 25 (2004)<br>Adv. X-ray Anal. 9, 344 (1966)</td><td>10.1007/s00604-003-0122-1<br>10.1007/978-1-4684-7633-0_31</td></tr><tr><td>Cs My</td><td>CsCl</td><td>J. Dellith</td><td>Microchim. Acta 145, 25 (2004)</td><td>10.1007/s00604-003-0122-1</td></tr><tr><td>Cs Mζ</td><td>CsCl</td><td>J. Dellith<br>F.D. Davidson</td><td>Microchim. Acta 145, 25 (2004)<br>Adv. X-ray Anal. 9, 344 (1966)</td><td>10.1007/s00604-003-0122-1<br>10.1007/978-1-4684-7633-0_31</td></tr><tr><td>Cs M4N3</td><td>CsCl</td><td>J. Dellith</td><td>Microchim. Acta 145, 25 (2004)</td><td>10.1007/s00604-003-0122-1</td></tr><tr><td rowspan="3">Cs 3d-5p</td><td rowspan="3">CsCl</td><td>J. Dellith</td><td>Microchim. Acta 145, 25 (2004)</td><td>10.1007/s00604-003-0122-1</td></tr><tr><td>P. Martin</td><td>J. Phys. Colloq. 48, C9-649 (1987)</td><td>10.1051/jphyscol:19879111</td></tr><tr><td>P. Motaïs<br>P. Motaïs</td><td>Phys. Rev. B. 25, 5492 (1982)<br>ISXRPAS 785 (1981)</td><td>10.1103/PhysRevB.25.5492<br>10.1007/978-1-4615-9236-5_152</td></tr><tr><td rowspan="3">Cs 3d-4f</td><td rowspan="3">CsCl</td><td>P. Motaïs</td><td>Phys. Rev. B. 25, 5492 (1982)</td><td>10.1103/PhysRevB.25.5492</td></tr><tr><td>P. Motaïs</td><td>ISXRPAS 785 (1981)</td><td>10.1007/978-1-4615-9236-5_152</td></tr><tr><td>P. Martin</td><td>J. Phys. Colloq. 48, C9-649 (1987)</td><td>10.1051/jphyscol:19879111</td></tr><tr><td rowspan="5">Cs N4,5O2,3</td><td>Cs</td><td>T.M. Zimkina</td><td>SPSS 15, 1786 (1974)</td><td></td></tr><tr><td>CsCl</td><td>M. Siegbahn</td><td>Z. Phys. 88, 559 (1934)</td><td>10.1007/BF01333107</td></tr><tr><td>CsI</td><td>M. Siegbahn</td><td>Z. Phys. 88, 559 (1934)</td><td>10.1007/BF01333107</td></tr><tr><td>Cs2O</td><td>V.A Fomichev</td><td>Phys.Scr. 41, 99 (1990)</td><td>10.1088/0031-8949/41/1/025</td></tr><tr><td>CsPbCl3</td><td>M. Terauchi</td><td>JEOL handbook (2021)</td><td>https://www.jeol.com/download soft x-ray.php</td></tr><tr><td rowspan="2">Cs O2,3</td><td>Cs</td><td>R.L. Fink</td><td>PRB 38, 5839 (1988)</td><td>10.1103/PhysRevB.38.5839</td></tr><tr><td>Cs/Ni</td><td>K.-D. Tsuei</td><td>PRL 71, 1099 (1993)</td><td>10.1103/PhysRevLett.71.1099</td></tr></tbody></table>

## Remarks and comments about the database

Figure 2(a) shows the evolution of the number of papers and of the number of cited papers through years, as soon as 1922, the year of the oldest article of the database. These two numbers differ since in a given article, the spectra of many materials can be present. Some interesting features can be noted:

* After a quite monotonous start, the number of papers takes a hold owing to the second world war (1939-1945); it is only 20 years after the end of the war that the number of papers returns to the pre-war number;

* The large number of cited papers in 2021 is explained by the introduction of the 2021 JEOL database [26]; the low number of cited papers in 2024 (the last displayed year) probably comes from an yet incomplete collection of the articles of this year;

* There is a peak for both numbers around 1970 for which the author has no clear explanation; perhaps this could be explained by the publication of Bearden's tables in 1967 [3], which disseminated quickly and after which it was not so urgent or interesting to investigate the x-ray emission of new materials;

* No relevant effect of the COVID19 crisis can be observed; a decrease is observed after 2020 but it is not significant enough;

* Up to 1990, both numbers of papers and cited papers follow the same trend;
Figure 2(b) displays, as a function of time, the ratio of the numbers of papers and cited papers, which represents the number of studied materials per article. It is observed that:

* The number of materials per article steadily diminishes with time;

* After 1990, the ratio seems to stabilize at around 4-5 entries per article of the database (the mean over the last 30 years is 5); this could be explained by the fact that now researchers study in their papers only a few (2-4) materials, together with a few reference materials (2-3), so present the spectra of a mean of 5 different materials. However, during the old years as the spectra of a lot of materials were unknown and the authors do not hesitate to present systematic studies of many materials in their articles. For example, the only article of 1923 [27] presents more than 90 different materials (mainly pure elements in this case).

<figure><img src="image_3.png" /><figcaption>Figure 2: (a) Evolution with time of the number of articles and of the number of cited articles; (b) evolution with time of the ratio of the number of cited papers to the number of papers, which represent the number of different materials in a single article. These curves have been established in April 2025 and not with the last version of the database.</figcaption></figure>

Table 1 gives the name of the top most cited authors in the database. It is dominated by Japanese, Russian, French, Indian, American and German scientists. The introduction of the JEOL database [26], encompassing about all the elements, makes Pr. M. Terauchi appearing the most times (a reference can occur many times in the database if it presents many spectra of various compounds, leading to a large number of occurrences of its author). The large number of occurrences collected by some authors, most of them no more in activity, is probably due to the fact that some years ago publications involved only a very small number of authors, one or two most of the time. Nowadays, many co-authors are included and generally students are put as first authors while the senior researcher appears at the last position in the author list. This makes that now there is more turnover of first authors and so it becomes difficult to accumulate a lot of occurrences in the database which presents only the first authors.

<table><caption>Table 1: List of authors having the most occurrences in the database (established in April 2025).</caption><tr><td>M. Terauchi</td><td>Japan</td><td>900</td><td>E.Z. Kurmaev</td><td>Russia</td><td>677</td></tr><tr><td>Y. Cauchois</td><td>France</td><td>433</td><td>G.N. Dolenko</td><td>Russia</td><td>427</td></tr><tr><td>J. Kawai</td><td>Japan</td><td>416</td><td>Y. Gohshi</td><td>Japan</td><td>390</td></tr><tr><td>L.N. Mazalov</td><td>Russia</td><td>365</td><td>H.S. Kainth</td><td>India</td><td>317</td></tr><tr><td>V.I. Nefedov</td><td>Russia</td><td>307</td><td>D.W. Fischer</td><td>USA</td><td>302</td></tr><tr><td>C. Bonnelle</td><td>France</td><td>285</td><td>E. Belin</td><td>France</td><td>270</td></tr></table>
<table><tr><td>G. Wiech</td><td>Germany</td><td>268</td><td>W.L. Baun</td><td>USA</td><td>267</td></tr><tr><td>G.B. Deodhar</td><td>India</td><td>263</td><td>V.V. Nemoshkalenko</td><td>Russia</td><td>252</td></tr><tr><td>E.P. Domashevskaya</td><td>Russia</td><td>230</td><td>O.I. Sumbaev</td><td>Russia</td><td>226</td></tr><tr><td>A. Meisel</td><td>Germany</td><td>215</td><td>M. Kavcic</td><td>Slovenia</td><td>200</td></tr><tr><td>...</td><td>...</td><td>...</td><td>P. Jonnard</td><td>France</td><td>146</td></tr></table>

## Conclusion

There are many spectroscopic ways to determine the chemical state of an element. Among them, x-ray photoelectron spectroscopy is perhaps the most widely disseminated. A correlation exists between shifts of XPS core levels and the ones of XES valence bands [28]. The measurement of chemical shift in x-ray absorption spectroscopy, as presented for instance in Ref. [29], is also relevant. XES combined to electron energy loss spectroscopy, also a chemically sensitive technique, enables obtaining a full picture of the electronic structure of a material [30]. So XES, is a powerful complement to other techniques but also on its own as it can be applied to all elements having an atomic number higher than 3, on all kinds of phases, on small and large thicknesses, upon various excitation conditions.

The present database is of high interest to prepare XES experiments on new materials, to check results obtained on new spectrometers, to complete or confirm chemical state determination obtained by XES or other means, such as the Kα/Kβ intensity ratio for instance. It can also be helpful to evidence changes in the shape of the valence band following reabsorption and satellite excitation as a function of the incident exciting energy or inclination of the sample. The database will also be useful for the establishment of training sets for models relying on artificial intelligence [31]. Most of the quantification processes performed on electron microprobes need measuring the intensity of an emission at its maximum, which implies that there is no significant shift of the maximum as a function of the chemical state, between the sample under study and the standard sample. The examination of the database will enable checking if this is assumption is correct or if the intensity should be rather taken as the area under the emission peak. Even prior to quantification, the database could be useful to have an idea of the chemical state of the emitting element: oxide, nitride, ..., metallic state. For the theoreticians, the database will enable comparing calculated energies of parent and satellite emissions, as well as the shape of the valence bands, obtained from the density functional theory for example. A final reason of the interest of the database will be to give priority to original works. It appears that some articles are published without references to previous studies. The availability and dissemination of the database will give credit to the rightful authors.

To obtain the database, please contact the author at the following address, philippe.jonnard@sorbonne-universite.fr, or at the generic address, sciences-lcpmr-database@sorbonne-universite.fr. The database will be provided in pdf format. The author thanks any colleague who can report error or can provide him with some articles not yet included in the database.

## Bibliography

1. Siegbahn, M. (1931) *Spektroskopie der Röntgenstrahlen*, Springer, Berlin, Heidelberg.

2. Cauchois, Y., et Hulubei, H. (1947) *Longueurs d'onde des émissions X et des discontinuités d'absorption X*, Hermann, Paris.

3. Bearden, J.A. (1967) X-Ray Wavelengths. *Rev. Mod. Phys.*, **39** (1), 78-124.

4. Cauchois, Y., et Sénémaud, C. (1978) *Tables of Wavelengths of X-Ray Emission Lines and Absorption Edges*, https://www.lcpmr.cnrs.fr/content/cauchois-and-sénémaud-tables-x-ray-wavelengths-download, Pergamon Press, Oxford.

5. Meisel, A., Leonhardt, G., et Szargan, R. (1989) *X-Ray Spectra and Chemical Binding*, Springer, Berlin, Heidelberg.
6. Deslattes, R.D., Kessler, E.G., Indelicato, P., de Billy, L., Lindroth, E., et Anton, J. (2003) X-ray transition energies: new approach to a comprehensive evaluation. *Rev. Mod. Phys.*, **75** (1), 35-99.

7. Deslattes, R.D., Kessler Jr., E.G., Indelicato, P., de Billy, L., Lindroth, E., Anton, J., Coursey, J.S., Schwab, D.J., Chang, J., Sukumar, R., Olsen, K., et Dragoset, R.A. (2005) X-Ray Transition Energies Database, https://www.nist.gov/pml/x-ray-transition-energies-database. *NIST Stand. Ref. Database*, **128**.

8. Zschornack, G.H. (2007) *Handbook of X-Ray Data*, Springer Science & Business Media, Berlin, Heidelberg.

9. Jonnard, P., et Bonnelle, C. (2011) Cauchois and Sénémaud Tables of wavelengths of X-ray emission lines and absorption edges. *X-Ray Spectrom.*, **40** (1), 12-16.

10. Kawai, J. (2023) *X-Ray Spectroscopy for Chemical State Analysis*, Springer Nature Singapore, Singapore.

11. CXRO X-ray interactions with matter, http://henke.lbl.gov/opticalarf constants/. X-Ray Interact. Matter.

12. XES OASIS, the XES Peak-Fitting Network Platform, https://xesoasis.org/.

13. Fabian, D.J. (éd.) (1968) *Soft x-ray band spectra and the electronic structure of metals and materials*, Academic Press, London, New York.

14. Azároff, L.V. (1974) *X-ray spectroscopy*, edited by Leonid V. Azaroff, McGraw-Hill, Inc., New York.

15. Bonnelle, C. (1987) Chapter 7. X-Ray spectroscopy. *Annu. Rep. Sect. C Phys. Chem.*, **84** (0), 201-272.

16. Bonnelle, C., Vergand, F., Jonnard, P., André, J.-M., Staub, P.F., Avila, P., Chargelègue, P., Fontaine, M.-F., Laporte, D., Paquier, P., Ringuenet, A., et Rodriguez, B. (1994) Instrument for research on interfaces and surfaces. *Rev. Sci. Instrum.*, **65** (11), 3466-3471.

17. Bonnelle, C., Jonnard, P., André, J.-M., Avila, A., Laporte, D., Ringuenet, H., Lépy, M.-C., Plagnard, J., Ferreux, L., et Protas, J.C. (2004) SOLEX: a tunable monochromatic X-ray source in the 1-20 keV energy range for metrology. *Nucl. Instrum. Methods Phys. Res. Sect. Accel. Spectrometers Detect. Assoc. Equip.*, **516** (2-3), 594-601.

18. Nicholls, C.J., et Urch, D.S. (1974) A study of the bonding in some compounds of aluminium using Al-Kβ1,3X-ray emission spectra. *J. Chem. Soc. Dalton Trans.*, (9), 901-907.

19. International Initiative on Fundamental Parameters – An international initiative on establishing accurate critical data for interactions of X-rays with matter (“fundamental parameters”), http://www.lnhb.fr/home/conferences-publications/iifp_wg/.

20. Terauchi, M., Murano, T., Takakura, M., et Takahashi, H. (2014) *Handbook of soft x-ray emission spectra Version 1.0* (Aug. 2014), IMRAM, Tokohu University, JEOL Ltd.

21. Terauchi, M., Koike, M., Takahashi, H., Takakura, M., Murano, T., et Koshiya, S. (2023) *Handbook of Soft X-ray Emission Spectra Version 8.0* (July. 2023) | Products | JEOL Ltd.

22. Search the CSIRO SXES Database, https://luminescence.csiro.au/sxes.

23. Zotero | Your personal research assistant, https://www.zotero.org/.

24. Scerri, E. (2013) *A Tale of Seven Elements*, Oxford University Press, Oxford, New York.

25. Jenkins, R., Manne, R., Robin, R., et Sénémaud, C. (1991) IUPAC—nomenclature system for x-ray spectroscopy. *X-Ray Spectrom.*, **20** (3), 149-155.

26. Terauchi, M., Takahashi, H., Takakura, M., Murano, T., et Koshiya, S. (2021) *Handbook of Soft X-ray Emission Spectra Version 7.0* (Dec. 2021), IMRAM, Tohoku University, JEOL Ltd.

27. Hjalmar, E. (1923) Roentgenspektroskopische Messungen Beitrag zur Kenntnis der Roentgenspektren. Z. Für Phys., **15** (1), 65-109.

28. Werme, L.O., Grennberg, B., Nordgren, J., Nordling, C., et Siegbahn, K. (1973) Correlation between core level chemical shifts obtained by ultrasoft X-ray emission and ESCA. *J. Electron Spectrosc. Relat. Phenom.*, **2** (5), 435-440.

29. Alonso Mori, R., Paris, E., Giuli, G., Eeckhout, S.G., Kavčič, M., Žitnik, M., Bučar, K., Pettersson, L.G.M., et Glatzel, P. (2009) Electronic Structure of Sulfur Studied by X-ray Absorption and Emission Spectroscopy. *Anal. Chem.*, **81** (15), 6516-6525.
30. Terauchi, M., Uemichi, Y., Ueda, H., Tsai, A.P., Takeuchi, T., et Mizutani, U. (2007) TEM spectroscopy study of electronic structures of quasicrystals and approximants. *Philos. Mag.*, **87** (18-21), 2947-2955.

31. Humiston, A., Lau, M.L., Stack, T., Restuccia, E., Herrera-Gomez, A., Long, M., Olive, D.T., et Terry, J. (2025) Analysis of x-ray emission spectroscopy (XES) data using artificial intelligence techniques included in the XES Neo package. *J. Vac. Sci. Technol. A*, **43** (4), 043411.

## Acknowledgments

Jonathan Dean (NIST, USA) and Polina Khadeeva (Petersburg State University, Russia) are thanked for their interest in the database. Colleagues from Sorbonne Université, at the CAMPARIS platform, Michel Fialin and Nicolas Rividi, at the LCPMR, particularly Tatiana Marchenko for traducing some Russian papers and from the IMSOX team, Karine Le Guen, are thanked for their help.

A CC-BY public copyright license has been applied by the authors to the present document and will be applied to all subsequent versions up to the Author Accepted Manuscript arising from this submission, in accordance with the grant's open access conditions.

This article is dedicated to the memory of Professor Christiane Bonnelle (1930-2016), who helped, encouraged and motivated me at the beginning of this work.

<figure><img src="image_4.png" /><figcaption>Professor Christiane Bonnelle (1930-2016) at her desk at the laboratoire de Chimie Physique of Pierre et Marie Curie street in Paris in 1986 (copyright laboratoire de Chimie Physique - Matière et Rayonnement, M.-F. Fontaine).</figcaption></figure>