TY  - JOUR
A1  - Born, Artur
A1  - Johansson, Fredrik O. L.
A1  - Leitner, Torsten
A1  - Bidermane, Ieva
A1  - Kuehn, Danilo
A1  - Martensson, Nils
A1  - Föhlisch, Alexander
T1  - The degree of electron itinerancy and shell closing in the core-ionized state of transition metals probed by Auger-photoelectron coincidence spectroscopy
JF  - Physical chemistry, chemical physics : a journal of European Chemical Societies
N2  - Auger-photoelectron coincidence spectroscopy (APECS) has been used to examine the electron correlation and itinerance effects in transition metals Cu, Ni and Co. 
It is shown that the LVV Auger, in coincidence with 2p photoelectrons, spectra can be represented using atomic multiplet positions if the 3d-shell is localized (atomic-like) and with a self-convoluted valence band for band-like (itinerant) materials as explained using the Cini-Sawatzky model. 
For transition metals, the 3d band changes from band-like to localized with increasing atomic number, with the possibility of a mixed behavior. 

Our result shows that the LVV spectra of Cu can be represented by atomic multiplet calculations, those of Co resemble the self-convolution of the valence band and those of Ni are a mixture of both, consistent with the Cini-Sawatzky model.
KW  - spectra
KW  - Ni
Y1  - 2022
U6  - https://doi.org/10.1039/d2cp02477b
SN  - 1463-9076
SN  - 1463-9084
VL  - 24
IS  - 32
SP  - 19218
EP  - 19222
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - GEN
A1  - Poch, Olivier
A1  - Istiqomah, Istiqomah
A1  - Quirico, Eric
A1  - Beck, Pierre
A1  - Schmitt, Bernard
A1  - Theulé, Patrice
A1  - Faure, Alexandre
A1  - Hily-Blant, Pierre
A1  - Bonal, Lydie
A1  - Kappel, David
T1  - Ammonium salts are a reservoir of nitrogen on a cometary nucleus and possibly on some asteroids
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - The measured nitrogen-to-carbon ratio in comets is lower than for the Sun, a discrepancy which could be alleviated if there is an unknown reservoir of nitrogen in comets. The nucleus of comet 67P/Churyumov-Gerasimenko exhibits an unidentified broad spectral reflectance feature around 3.2 micrometers, which is ubiquitous across its surface. On the basis of laboratory experiments, we attribute this absorption band to ammonium salts mixed with dust on the surface. The depth of the band indicates that semivolatile ammonium salts are a substantial reservoir of nitrogen in the comet, potentially dominating over refractory organic matter and more volatile species. Similar absorption features appear in the spectra of some asteroids, implying a compositional link between asteroids, comets, and the parent interstellar cloud.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1389 
KW  - resolution infrared-spectroscopy
KW  - ice absorption features
KW  - young stellar objects
KW  - exposed water ice
KW  - MU-M
KW  - bidirectional reflectance
KW  - murchison meteorite
KW  - interstellar ice
KW  - spectra
KW  - surface
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-513751
SN  - 1866-8372
N1  - This secondary publication was withdrawn for copyright reasons.
IS  - 6483
ER  - 
TY  - JOUR
A1  - Poch, Olivier
A1  - Istiqomah, Istiqomah
A1  - Quirico, Eric
A1  - Beck, Pierre
A1  - Schmitt, Bernard
A1  - Theulé, Patrice
A1  - Faure, Alexandre
A1  - Hily-Blant, Pierre
A1  - Bonal, Lydie
A1  - Kappel, David
T1  - Ammonium salts are a reservoir of nitrogen on a cometary nucleus and possibly on some asteroids
JF  - Science
N2  - The measured nitrogen-to-carbon ratio in comets is lower than for the Sun, a discrepancy which could be alleviated if there is an unknown reservoir of nitrogen in comets. The nucleus of comet 67P/Churyumov-Gerasimenko exhibits an unidentified broad spectral reflectance feature around 3.2 micrometers, which is ubiquitous across its surface. On the basis of laboratory experiments, we attribute this absorption band to ammonium salts mixed with dust on the surface. The depth of the band indicates that semivolatile ammonium salts are a substantial reservoir of nitrogen in the comet, potentially dominating over refractory organic matter and more volatile species. Similar absorption features appear in the spectra of some asteroids, implying a compositional link between asteroids, comets, and the parent interstellar cloud.
KW  - resolution infrared-spectroscopy
KW  - ice absorption features
KW  - young stellar objects
KW  - exposed water ice
KW  - MU-M
KW  - bidirectional reflectance
KW  - murchison meteorite
KW  - interstellar ice
KW  - spectra
KW  - surface
Y1  - 2020
U6  - https://doi.org/10.1126/science.aaw7462
SN  - 1095-9203
SN  - 0036-8075
VL  - 367
IS  - 6483
SP  - 1
EP  - 8
PB  - AAAS, American Association for the Advancement of Science
CY  - Washington, DC
ER  -