1,721,149 research outputs found
Improved depth information from routine analysis of the inelastic background of XPS and HAXPES spectra using optimized two‐ and three‐parameter cross‐sections
Full text linkDetermination of the depth distribution of complex nanostructures by X-ray photoelectron spectroscopy (XPS) inelastic background analysis may be complicated if the sample materials have widely different inelastic scattering cross-sections. It was recently demonstrated that this may be solved by using a mixture of cross-sections. This permits retrieval of depth distributions of complex stacks and deeply buried layers with a typical 5% accuracy. This requires however that the cross-sections of the individual sample materials are known which is often not the case and this can complicate practical use for routine analysis. In this paper, we explore to what extent a suitable two- or three-parameter cross-section can be defined independent of prior knowledge of the cross-sections involved but simply defined by fitting the cross-section parameters to the spectrum being analyzed. This paper presents a theoretical study following our recent paper that explored how to make the best choice of inelastic mean free path and inelastic scattering cross-section for the inelastic background analysis with the Quases-Tougaard software. It was previously shown that a rough analysis of the inelastic background could give a good idea of the depth distribution. Here, we demonstrate with model spectra from buried layers created with Quases-Tougaard Generate software that a rather accurate analysis can be performed for very different cases with an average ~5% error. This analysis is easy to apply as it only needs the two- or three-parameter cross-sections generated with the Quases-Tougaard software. This study is aimed to improve routine analysis of the inelastic background of XPS and hard X-ray photoelectron spectroscopy (HAXPES) spectra.</p
QUEELS-XPS: Software to calculate the energy loss processes in XPS and AES including the effects of the core hole.
No full textXPS spectra consist of the primary photo-excited core electrons, including processes such as lifetime broadening, spin-orbit coupling, and multiplet splitting. On top of this, there is a background of energy-loss structures caused by excitations due to the sudden creation of the static core hole and due to electron transport out of the surface (including bulk and surface effects). The corresponding energy-loss processes are usually denoted ‘‘intrinsic’’ and ‘‘extrinsic’’ excitations. The QUEELS-XPS software calculates these effects quantitatively by a dielectric response description. It also applies to AES. The only input in the software is the dielectric function expressed by the energy loss function (ELF). The ELF for various materials is available at:
Pauly, Nicolas, Yubero, Francisco, & Tougaard, Sven. (2022). ELF dielectric functions for various materials. (1.0) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.6024064
The QUEELS-XPS software was first presented in the paper
Software package to calculate the effects of the core hole and surface excitations on XPS and AES
S. Tougaard and F. Yubero, Surface Interface Analysis 44, 1114-1118 (2012)
Note: The QUEELS-XPS software will be available here soon and can presently be downloaded at http://quases.com/products/queels-xps/
The QUEELS-XPS software is an extension of the QUEELS software which applies to EELS, REELS, AES, and XPS. QUEELS is presented in the paper "QUEELS: Software to calculate the energy loss processes in TEELS, REELS, XPS and AES including effects of the core hole"; by S. Tougaard, N. Pauly, F. Yubero, Surf. Interf Anal (2022) http://doi.org/10.1002/sia.7095. The QUEELS software can be downloaded here:
Tougaard, Sven, & Yubero, Francisco. (2022). QUEELS software for calculation of energy loss processes in TEELS, REELS, XPS, and AES including effects of the core hole (2.3). Zenodo. https://doi.org/10.5281/zenodo.6022426
Recent applications of QUEELS-XPS:
XPS primary excitation spectra of Zn 2p, Fe 2p, and Ce 3d from ZnO, α-Fe2O3, and CeO2
N. Pauly, F. Yubero, J.P. Espinós, S. Tougaard. Surface and Interface Analysis 51, 353-360 (2019) https://doi.org/10.1002/sia.6587
Quantitative analysis of Yb 4d photoelectron spectrum of metallic Yb
N. Pauly, F. Yubero, S. Tougaard, Surface and Interface Analysis 50, 1168-1173 (2018); https://doi.org/10.1002/sia.6402
Quantitative analysis of satellite structures in XPS spectra of gold and silver
N. Pauly, F. Yubero, S. Tougaard, Applied Surface Science 383, 317–323 (2016); http://dx.doi.org/10.1016/j.apsusc.2016.03.185
Quantitative analysis of Ni 2p photoemission in NiO and Ni diluted in a SiO2 matrix
N. Pauly, F. Yubero, F.J. García-García, S. Tougaard, Surf. Sci. 644, 46-52 (2016) http://dx.doi.org/10.1016/j.susc.2015.09.012
LMM Auger primary excitation spectra of copper
N. Pauly, S. Tougaard, F. Yubero, Surface Science 630, 294–299 (2014) http://dx.doi.org/10.1016/j.susc.2014.08.029
Modeling of X-ray photoelectron spectra: surface and core hole effects
N. Pauly, F. Yubero, S. Tougaard, Surface and Interface Analysis 46, 920-923 (2014) ; http://dx.doi.org/10.1002/sia.5372
Determination of the Cu 2p primary excitation spectra for Cu, Cu2O and CuO
N. Pauly, S. Tougaard, F. Yubero, Surface Science 620, 17-22 (2014); http://dx.doi.org/10.1016/j.susc.2013.10.009
Dielectric description of the angular dependence of the loss structure in core level photoemission
F. Yubero and S. Tougaard, J. Electron Spectroscopy and Related Phenomena 185 (2012) 552-5
QUEELS software for calculation of energy loss processes in TEELS, REELS, XPS, and AES including effects of the core hole
No full textQUEELS is for calculation of energy loss processes in TEELS, REELS, XPS, and AES including effects of the core hole
It is based on a dielectric response description of the interaction of the moving electron with the electrons of the solid and includes the boundary effects imposed by the particular experimental situation. Its validity has been verified in several experiments.
The QUEELS software can be downloaded at: doi: 10.5281/zenodo.6022426
QUEELS is free to use for non-commercial applications.
The software is based on theory published in the papers:
1. J. Lindhard, Kgl Danske Vid Selsk Mat-Fys Medd 28:8 (1954)
2. R H. Ritchie, Phys. Rev. 106, p. 874 (1957)
3. F. Yubero and S. Tougaard, Phys. Rev. B46, p. 2486, (1992)
4. F. Yubero, JM Sanz, B. Ramskov, S. Tougaard, Phys. Rev. B53, p. 9719,(1996)
5. AC. Simonsen, F. Yubero, S. Tougaard, Phys. Rev. B56, p. 1612, (1997)
A brief summary of the theory behind QUEELS and discussion of its practical application is published in the paper which can be downloaded here: :https://doi-org.proxy1-bib.sdu.dk/10.1002/sia.7095.
S. Tougaard, N. Pauly, F. Yubero, QUEELS: Software to calculate the energy loss processes in TEELS, REELS, XPS, and AES including effects of the core hole, Surf. Interf. Anal. 54, p. 820-833 (2022).
A brief users guide is available in the supplementary material to this paper.
The only input needed in QUEELS is the dielectric function of the material expressed by the so called energy loss function (ELF) as a sum of oscillators.
You may get acquainted with the software by reproducing the spectra shown in the guide and the abovementioned paper for Au and Si.
To do this, you first copy the files ELF_Au.txt and ELF_Si.txt into a folder e.g. C:\ELF\ELF_Au.txt. Then read the file with the "Set Material Parameters" menu in QUEELS.
ELF for a range of other materials can be found in:
Pauly, Nicolas, Yubero, Francisco, & Tougaard, Sven. (2022). ELF dielectric functions for various materials. (1.0) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.6024064
Copyright (c) 2001-2022 All rights reserved
QUEELS software is developed by Sven Tougaard and Francisco Yubero
Sven Tougaard, Dept of Physics, Chemistry, and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark
Francisco Yubero, Inst. de Ciencia de Materiales de Sevilla, Isla de la Cartuja, E-41092 Sevilla, Spain
(e-mails: [email protected] and [email protected]
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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