Unifit 2002—universal analysis software for photoelectron spectra

Hesse, R.; Chassé, T.; Szargan, R.

doi:10.1007/s00216-002-1705-0

Cited by 65 publications

(52 citation statements)

References 3 publications

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“…26) software. For the UPS and IPS data Gaussian peaks and polynomial backgrounds 12 and for the XPS data, Voigt peaks and Shirley backgrounds 26 were employed in the fitting routine.…”

Section: Methodsmentioning

confidence: 99%

Transport band gap opening at metal–organic interfaces

Haidu

Salvan

Zahn

et al. 2014

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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The interface formation between copper phthalocyanine (CuPc) and two representative metal substrates, i.e., Au and Co, was investigated by the combination of ultraviolet photoelectron spectroscopy and inverse photoelectron spectroscopy. The occupied and unoccupied molecular orbitals and thus the transport band gap of CuPc are highly influenced by film thickness, i.e., molecule substrate distance. Due to the image charge potential given by the metallic substrates the transport band gap of CuPc "opens" from (1.4 ± 0.3) eV for 1 nm thickness to (2.2 ± 0.3) eV, and saturates at this value above 10 nm CuPc thickness. The interface dipoles with values of 1.2 eV and 1.0 eV for Au and Co substrates, respectively, predominantly depend on the metal substrate work functions. X-ray photoelectron spectroscopy measurements using synchrotron radiation provide detailed information on the interaction between CuPc and the two metal substrates. While charge transfer from the Au or Co substrate to the Cu metal center is present only at sub-monolayer coverages, the authors observe a net charge transfer from the molecule to the Co substrate for films in the nm range. Consequently, the Fermi level is shifted as in the case of a p-type doping of the molecule. This is, however, a competing phenomenon to the energy band shifts due to the image charge potential.

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“…26) software. For the UPS and IPS data Gaussian peaks and polynomial backgrounds 12 and for the XPS data, Voigt peaks and Shirley backgrounds 26 were employed in the fitting routine.…”

Section: Methodsmentioning

confidence: 99%

Transport band gap opening at metal–organic interfaces

Haidu

Salvan

Zahn

et al. 2014

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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“…Here, either Koopmans' interpretation of the orbital energies or the Mulliken net atomic charges is used. Figure 3 shows the fits to the C1s core levels of cytosine ( [ 22] This figure includes the experimental spectra, the fit components with background lines, and the shape of the fit residuals. The fits are performed with identical Voigt profiles for each component.…”

Section: X-ray Photoemission Spectroscopymentioning

confidence: 99%

Thin‐Film Properties of DNA and RNA Bases: A Combined Experimental and Theoretical Study

et al. 2008

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The structures of the DNA and RNA bases cytosine, uracil, and thymine in thin films with a nominal film thickness of about 20 nm are studied by using X-ray photoemission spectroscopy (XPS) and Fourier-transform infrared spectroscopy. The molecules are evaporated in situ from powder on a gold foil. The experimental results indicate that cytosine is composed of two energetically close tautomeric forms, whereas uracil and thymine exist in only one tautomeric form. Additionally, quantum chemical calculations are performed to complement the experimental results. The relative energies of the tautomeric forms of cytosine, uracil, and thymine are calculated using Hartree-Fock (HF), density functional theory (DFT), and post-HF methods. Furthermore, the assignment of the XPS spectra is supported by using simple model considerations employing Koopmans ionization energies and Mulliken net atomic charges.

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“…Under the measuring conditions, the FWHM of the Ag3d 5/2 peak was 1.49 eV at 50 eV pass energy and 1.0 eV for 10 eV pass energy. The composition of samples was quantified using Unifit Version 8.0 (Hesse et al, 2003). Peaks present in the spectra (O1s, C1s, N1s, P2p, Cl2p3, Al2p, Na2s) were referenced to the C signal at 285.0 eV, integrated and quantified using the manufacturer-based sensitivity factors.…”

Section: X-ray Photoelectron Spectroscopy (Xps)mentioning

confidence: 99%

“…15). To quantify relative changes between unreacted and adsorbed EPS, we integrated selected spectral regions in the 800À1800 cm À1 range after fitting a Shirleybackground and normalizing each full spectrum to unity absorbance (Unifit 8.0; Hesse et al, 2003). Integrated peak areas were obtained for the following functional units: polysaccharide/organic P (900À1200 cm À1 ), amide I (1600À1750 cm ).…”

Section: Eps Surveymentioning

confidence: 99%

Stabilization of extracellular polymeric substances (Bacillus subtilis) by adsorption to and coprecipitation with Al forms

Mikutta

Zang

Chorover

et al. 2011

Geochimica et Cosmochimica Acta

108

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Stabilization of extracellular polymeric substances (Bacillus subtilis) by adsorption to and coprecipitation with Al forms Mikutta, R.; Zang, U.; Chorover, J.; Haumaier, L.; Kalbitz, K. General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Abstract Extracellular polymeric substances (EPS) are continuously produced by bacteria during their growth and metabolism. In soils, EPS are bound to cell surfaces, associated with biofilms, or released into solution where they can react with other solutes and soil particle surfaces. If such reaction results in a decrease in EPS bioaccessibility, it may contribute to stabilization of microbial-derived organic carbon (OC) in soil. Here we examined: (i) the chemical fractionation of EPS produced by a common Gram positive soil bacterial strain (Bacillus subtilis) during reaction with dissolved and colloidal Al species and (ii) the resulting stabilization against desorption and microbial decay by the respective coprecipitation (with dissolved Al) and adsorption (with Al(OH) 3(am) ) processes. Coprecipitates and adsorption complexes obtained following EPS-Al reaction as a function of pH and ionic strength were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The stability of adsorbed and coprecipitated EPS against biodegradation was assessed by mineralization experiments for 1100 h. Up to 60% of the initial 100 mg/L EPS-C was adsorbed at the highest initial molar Al:C ratio (1.86), but this still resulted only in a moderate OC mass fraction in the solid phase (17 mg/g Al(OH) 3(am) ). In contrast, while coprecipitation by Al was less efficient in removing EPS from solution (maximum values of 33% at molar Al:C ratios of 0.1-0.2), the OC mass fraction in the solid product was substantially larger than that in adsorption complexes. Organic P compounds were preferentially bound during both adsorption and coprecipitation. Data are consistent with strong ligand exchange of EPS phosphoryl groups during adsorption to Al(OH) 3(am) , whereas for coprecipitation weaker sorption mechanisms are also involved. X-ray photoelectron analyses indicate an intimate mixing of EPS with Al in the coprecipitates, which is not observed in the case of EPS adsorption complexes. The incubation experiments...

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Unifit 2002—universal analysis software for photoelectron spectra

Cited by 65 publications

References 3 publications

Transport band gap opening at metal–organic interfaces

Transport band gap opening at metal–organic interfaces

Thin‐Film Properties of DNA and RNA Bases: A Combined Experimental and Theoretical Study

Stabilization of extracellular polymeric substances (Bacillus subtilis) by adsorption to and coprecipitation with Al forms

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