XPS and Ag L3-edge XANES characterization of silver and silver–gold sulfoselenides. / Mikhlin, Yuri L.; Pal'yanova, Galina A.; Tomashevich, Yevgeny V. et al.
In: Journal of Physics and Chemistry of Solids, Vol. 116, 01.05.2018, p. 292-298.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - XPS and Ag L3-edge XANES characterization of silver and silver–gold sulfoselenides
AU - Mikhlin, Yuri L.
AU - Pal'yanova, Galina A.
AU - Tomashevich, Yevgeny V.
AU - Vishnyakova, Elena A.
AU - Vorobyev, Sergey A.
AU - Kokh, Konstantin A.
PY - 2018/5/1
Y1 - 2018/5/1
N2 - Gold and silver sulfoselenides are of interest as materials with high ionic conductivity and promising magnetoresistive, thermoelectric, optical, and other physico-chemical properties, which are strongly dependent on composition and structure. Here, we applied X-ray photoelectron spectroscopy and Ag L3 X-ray absorption near-edge structure (XANES) to study the electronic structures of low-temperature compounds and solid solutions Ag2SxSe1–x (0 < x < 1), AgAuS, and Ag3AuSxSe2–x (x = 0, 1, 2). Upon substitution of Se with S, a steady increase in the positive charge at Ag(I) sites and only minor changes in the local charge at chalcogen atoms were found from the photoelectron Ag 3d, S 2p, Se 3d, and Ag M4,5VV Auger spectra. The intensity of the Ag L3-edge peak, which is known to correlate with hole counts in the Ag 4d shell having a formal d10 configuration, was enhanced by 20–25% from Ag2Se to Ag2S and from Ag3AuSe2 to Ag3AuS2. The effect of gold is more pronounced, and the number of Ag d holes and the negative charge of S and Se notably decreased for Au-containing compounds; in particular, the Ag L3-edge peak is about 35% lower for AgAuS relative to Ag2S. At the same time, the Au 4f binding energy and, therefore, charge at Au(I) sites increase with increasing S content due to the transfer of electron density from Au to Ag atoms. It was concluded that the effects mainly originate from shortening of the metal–chalcogen and especially the Au–Ag interatomic distances in substances having similar coordination geometry.
AB - Gold and silver sulfoselenides are of interest as materials with high ionic conductivity and promising magnetoresistive, thermoelectric, optical, and other physico-chemical properties, which are strongly dependent on composition and structure. Here, we applied X-ray photoelectron spectroscopy and Ag L3 X-ray absorption near-edge structure (XANES) to study the electronic structures of low-temperature compounds and solid solutions Ag2SxSe1–x (0 < x < 1), AgAuS, and Ag3AuSxSe2–x (x = 0, 1, 2). Upon substitution of Se with S, a steady increase in the positive charge at Ag(I) sites and only minor changes in the local charge at chalcogen atoms were found from the photoelectron Ag 3d, S 2p, Se 3d, and Ag M4,5VV Auger spectra. The intensity of the Ag L3-edge peak, which is known to correlate with hole counts in the Ag 4d shell having a formal d10 configuration, was enhanced by 20–25% from Ag2Se to Ag2S and from Ag3AuSe2 to Ag3AuS2. The effect of gold is more pronounced, and the number of Ag d holes and the negative charge of S and Se notably decreased for Au-containing compounds; in particular, the Ag L3-edge peak is about 35% lower for AgAuS relative to Ag2S. At the same time, the Au 4f binding energy and, therefore, charge at Au(I) sites increase with increasing S content due to the transfer of electron density from Au to Ag atoms. It was concluded that the effects mainly originate from shortening of the metal–chalcogen and especially the Au–Ag interatomic distances in substances having similar coordination geometry.
KW - Electronic structure
KW - Silver sulfoselenides
KW - Silver–gold sulfoselenides
KW - X-ray absorption near-edge structure
KW - X-ray photoelectron spectroscopy
KW - SYSTEM
KW - Silver-gold sulfoselenides
KW - THERMODYNAMIC PROPERTIES
KW - SELENIUM ISOMORPHOUS SUBSTITUTION
KW - SULFIDES
KW - CRYSTAL-STRUCTURE
KW - SOLID-SOLUTIONS
KW - NEAR-EDGE-STRUCTURE
KW - TRANSITION
KW - RAY PHOTOELECTRON-SPECTROSCOPY
KW - ELECTRONIC-STRUCTURE
UR - http://www.scopus.com/inward/record.url?scp=85041388113&partnerID=8YFLogxK
U2 - 10.1016/j.jpcs.2018.01.047
DO - 10.1016/j.jpcs.2018.01.047
M3 - Article
AN - SCOPUS:85041388113
VL - 116
SP - 292
EP - 298
JO - Journal of Physics and Chemistry of Solids
JF - Journal of Physics and Chemistry of Solids
SN - 0022-3697
ER -
ID: 9539788