3dcore-level x-ray photoelectron spectroscopy of EuCu2Si2, a mixed-valence system

1981 ◽  
Vol 23 (8) ◽  
pp. 4283-4285 ◽  
Author(s):  
L. C. Gupta ◽  
E. V. Sampathkumaran ◽  
R. Vijayaraghavan ◽  
Varsha Prabhawalkar ◽  
P. D. Prabhawalkar ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mixed Valence ◽  
X Ray

scholarly journals A novel and potentially scalable CVD-based route towards SnO2:Mo thin films as transparent conducting oxides

2021 ◽  
Author(s):  
Tianlei Ma ◽  
Marek Nikiel ◽  
Andrew G. Thomas ◽  
Mohamed Missous ◽  
David J. Lewis
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Mixed Valence ◽  
Chemical Vapour ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conducting Oxides ◽  
Valence States ◽  
3 Omega ◽  
First Time

AbstractIn this report, we prepared transparent and conducting undoped and molybdenum-doped tin oxide (Mo–SnO2) thin films by aerosol-assisted chemical vapour deposition (AACVD). The relationship between the precursor concentration in the feed and in the resulting films was studied by energy-dispersive X-ray spectroscopy, suggesting that the efficiency of doping is quantitative and that this method could potentially impart exquisite control over dopant levels. All SnO2 films were in tetragonal structure as confirmed by powder X-ray diffraction measurements. X-ray photoelectron spectroscopy characterisation indicated for the first time that Mo ions were in mixed valence states of Mo(VI) and Mo(V) on the surface. Incorporation of Mo6+ resulted in the lowest resistivity of $$7.3 \times 10^{{ - 3}} \Omega \,{\text{cm}}$$ 7.3 × 10 - 3 Ω cm , compared to pure SnO2 films with resistivities of $$4.3\left( 0 \right) \times 10^{{ - 2}} \Omega \,{\text{cm}}$$ 4.3 0 × 10 - 2 Ω cm . Meanwhile, a high transmittance of 83% in the visible light range was also acquired. This work presents a comprehensive investigation into impact of Mo doping on SnO2 films synthesised by AACVD for the first time and establishes the potential for scalable deposition of SnO2:Mo thin films in TCO manufacturing. Graphical abstract

scholarly journals Growth and Characterisation Studies of Eu3O4 Thin Films Grown on Si/SiO2 and Graphene

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1598
Author(s):  
Razan O. M. Aboljadayel ◽  
Adrian Ionescu ◽  
Oliver J. Burton ◽  
Gleb Cheglakov ◽  
Stephan Hofmann ◽  
...  
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Molecular Beam ◽  
Mixed Valence ◽  
Oxide Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sio2 Substrate ◽  
Optical Images ◽  
The Eu

We report the growth, structural and magnetic properties of the less studied Eu-oxide phase, Eu3O4, thin films grown on a Si/SiO2 substrate and Si/SiO2/graphene using molecular beam epitaxy. The X-ray diffraction scans show that highly textured crystalline Eu3O4(001) films are grown on both substrates, whereas the film deposited on graphene has a better crystallinity than that grown on the Si/SiO2 substrate. The SQUID measurements show that both films have a Curie temperature of ∼5.5±0.1 K, with a magnetic moment of ∼320 emu/cm3 at 2 K. The mixed valence of the Eu cations has been confirmed by the qualitative analysis of the depth-profile X-ray photoelectron spectroscopy measurements with the Eu2+:Eu3+ ratio of 28:72. However, surprisingly, our films show no metamagnetic behaviour as reported for the bulk and powder form. Furthermore, the microscopic optical images and Raman measurements show that the graphene underlayer remains largely intact after the growth of the Eu3O4 thin films.

scholarly journals Mixed Valence of Ce and Its Consequences on the Magnetic State of Ce9Ru4Ga5: Electronic Structure Studies

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2377
Author(s):  
Andrzej Ślebarski ◽  
Józef Deniszczyk ◽  
Dariusz Kaczorowski
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Photoelectron Spectroscopy ◽  
Magnetic State ◽  
Mixed Valence ◽  
Xps Spectra ◽  
X Ray ◽  
Tetragonal Unit Cell ◽  
Intermediate Valent ◽  
Structure Investigations

We report on X-ray photoelectron spectroscopy (XPS) and ab initio electronic structure investigations of a novel intermetallic material Ce 9 Ru 4 Ga 5 . The compound crystallizes with a tetragonal unit cell (space group I4 m m ) that contains three inequivalent Ce atoms sites. The Ce 3 d core level XPS spectra indicated an intermediate valence (IV) of selected Ce ions, in line with the previously reported thermodynamic and spectroscopic data. The ab initio calculations revealed that Ce1 ions located at 2 a Wyckoff positions possess stable trivalent configuration, whereas Ce2 ions that occupy 8 d site are intermediate valent. Moreover, for Ce3 ions, located at different 8 d position, a fractional valence was found. The results are discussed in terms of on-site and intersite hybridization effects.

Characterization and Rietveld refinements of new dense ceramics Ba3−xSrxTb3−xCexO9 (x = 1 and 1.5) perovskites

2020 ◽  
Vol 35 (1) ◽  
pp. 23-30
Author(s):  
Yali Su ◽  
Dayong Lu ◽  
Shan Wang
Keyword(s):  
Electrical Conductivity ◽  
Photoelectron Spectroscopy ◽  
Mixed Oxides ◽  
Mixed Valence ◽  
Electrical Measurements ◽  
Paramagnetic Resonance ◽  
Space Group ◽  
X Ray ◽  
Valence States ◽  
Trigonal Structure

Ba3−xSrxTb3−xCexO9 (x = 1 and 1.5) ceramics (BSTC) with a relative density of 93% and a grain size distribution of 0.2–3 µm were prepared by the mixed-oxides reaction route. The crystalline structures, microstructures, valence states, and electrical properties of two ceramics were analyzed using X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), and electrical measurements. Rietveld analyses of XRPD patterns show that BSTC1 is indexed as a trigonal structure with the space group R-3c, and BSTC3/2 is indexed as an orthorhombic perovskite structure with the space group Pmcn. The EPR, XPS, and electrical conductivity results confirm that Ce and Tb ions in BSTC exist as Ce4+ and mixed-valence states of Tb4+/Tb3+, respectively. At room temperature, the two BSTC ceramics exhibit a similar semiconducting behavior. The relationships between electrical conductivity and temperature/frequency are provided. The defect chemistry is discussed.

3d and 4d core level X-ray photoelectron spectroscopy of mixed-valence CePd3

1980 ◽  
Vol 13 (18) ◽  
pp. L455-L457 ◽  
Author(s):  
L C Gupta ◽  
E V Sampathkumaran ◽  
R Vijayaraghavan ◽  
M S Hegde ◽  
C N R Rao
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mixed Valence ◽  
Core Level ◽  
X Ray
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