Auger parameter in X-ray photoelectron spectroscopy of perovskite-type mixed oxides (La1-xMxCoO3, x=0-0.5, M: Ce, Sr)

1987 ◽  
Vol 28 (1) ◽  
pp. 85-91 ◽  
Author(s):  
Shigemi Kohiki ◽  
Shinji Ozaki ◽  
Tomoko Hamada ◽  
Kenji Tabata
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mixed Oxides ◽  
X Ray ◽  
Auger Parameter ◽  
Perovskite Type

scholarly journals Bulk Versus Surface Modification of Alumina with Mn and Ce Based Oxides for CH4 Catalytic Combustion

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1771 ◽  
Author(s):  
Stefan Neatu ◽  
Mihaela M. Trandafir ◽  
Adelina Stănoiu ◽  
Ovidiu G. Florea ◽  
Cristian E. Simion ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Combustion ◽  
Mixed Oxides ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Catalytic Combustion Of Methane ◽  
Adsorption Desorption

This study presents the synthesis and characterization of lanthanum-modified alumina supported cerium–manganese mixed oxides, which were prepared by three different methods (coprecipitation, impregnation and citrate-based sol-gel method) followed by calcination at 500 °C. The physicochemical properties of the synthesized materials were investigated by various characterization techniques, namely: nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and H2–temperature programmed reduction (TPR). This experimental study demonstrated that the role of the catalytic surface is much more important than the bulk one. Indeed, the incipient impregnation of CeO2–MnOx catalyst, supported on an optimized amount of 4 wt.% La2O3–Al2O3, provided the best results of the catalytic combustion of methane on our catalytic micro-convertors. This is mainly due to: (i) the highest pore size dimensions according to the Brunauer-Emmett-Teller (BET) investigations, (ii) the highest amount of Mn4+ or/and Ce4+ on the surface as revealed by XPS, (iii) the presence of a mixed phase (Ce2MnO6) as shown by X-ray diffraction; and (iv) a higher reducibility of Mn4+ or/and Ce4+ species as displayed by H2–TPR and therefore more reactive oxygen species.

Characterization of silicon compounds using the Auger parameter in X-ray Photoelectron Spectroscopy (XPS)

1987 ◽  
Vol 28 (2) ◽  
pp. 103-110 ◽  
Author(s):  
Shigemi Kohiki ◽  
Shinji Ozaki ◽  
Tomoko Hamada ◽  
Kazuo Taniguchi
Keyword(s):  
Photoelectron Spectroscopy ◽  
Silicon Compounds ◽  
X Ray ◽  
Auger Parameter

scholarly journals On tuning architectonics of nanoscaled assemblies of Zn-Ga-Al -based oxides obtained from layered double hydroxides precursors

2019 ◽  
Author(s):  
Corina E Ignat ◽  
Gabriela Carja ◽  
Laura E Romila ◽  
Doina Lutic
Keyword(s):  
Electron Microscopy ◽  
Layered Double Hydroxides ◽  
Photoelectron Spectroscopy ◽  
Mixed Oxides ◽  
Thermal Transformation ◽  
Thermal Analyses ◽  
Advanced Materials ◽  
X Ray ◽  
Calcination Temperatures ◽  
Double Hydroxides

Nanoscaled self-assemblies with engineered architectonics are important for obtaining advanced materials with specific applications in nanotechnology. We investigated here the morphology features at the nanoscale of the assemblies of the mixed oxides obtained through the thermal transformation of Zn2+Me3+ (Me=Al/Ga) layered double hydroxides (LDHs), as their “as-synthesized” form or after they were reconstructed in the aqueous solution of Ga2(SO4)3. The characteristics of ZnMe LDHs and the derived assemblies of mixed oxides were assessed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM/EDX), N2 adsorption at −196°C and thermal analyses (TG/DTG/DSC). The results revealed the formation nanoscaled assemblies of ZnO/ZnAl2O4/ZnGa2O4 and ZnO/Ga2O3/ZnGa2O4 starting from ZnMe(Me=Al/Ga) as precursors. Results point out that both the composition of the LDHs and the calcination temperatures can be used as parameters for tuning the nanomorphology features of the studied mixed oxides.

scholarly journals Improvement of Sensing Performance of Impedancemetric C2H2 Sensor Using SmFeO3 Thin-Films Prepared by a Polymer Precursor Method

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 773 ◽  
Author(s):  
Tomohisa Tasaki ◽  
Satoko Takase ◽  
Youichi Shimizu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Precursor Solution ◽  
Particle Growth ◽  
Polymer Precursor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensor Material ◽  
Perovskite Type

A sensitive an impedancemetric acetylene (C2H2) gas sensor device could be fabricated by using perovskite-type SmFeO3 thin-film as a sensor material. The uniform SmFeO3 thin-films were prepared by spin-coating and focusing on the effects of polymer precursor solutions. The prepared precursors and thin-films were characterized by means of thermal analysis,　Fourier-transform infrared spectroscopy, ultraviolet–visible spectroscopy, X-ray diffraction analysis, scanning electron microscopy and X-ray photoelectron spectroscopy . It was found that particle growth and increase in homogeneity of the prepared thin-film could be accelerated by the addition of acetyl acetone (AcAc) as a coordination agent in the polymer precursor solution. Moreover, the highly crystallized thin-film-based sensor showed good response properties and stabilities to a low C2H2 concentration between 0.5 and 2.0 ppm.

The use of Ols charge referencing for the X-ray photoelectron spectroscopy of Al/Si, AI/Ti and Al/Zr mixed oxides

1997 ◽  
Vol 16 (1) ◽  
pp. 1-3 ◽  
Author(s):  
A. K. BHATTACHARYA ◽  
D. R. PYKE ◽  
R. REYNOLDS ◽  
G. S. WALKER ◽  
A. K. BHATTACHARYA
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mixed Oxides ◽  
X Ray

scholarly journals Effect of the Incorporation of Titanium on the Optical Properties of ZnO Thin Films: From Doping to Mixed Oxide Formation

Coatings ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 180 ◽  
Author(s):  
Miriam Yuste ◽  
Ramon Escobar-Galindo ◽  
Noelia Benito ◽  
Carlos Palacio ◽  
Oscar Martínez ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mixed Oxides ◽  
Energy Gap ◽  
Amorphous Structure ◽  
Zno Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Wide Range ◽  
Ti Content

ZnO films with Ti atoms incorporated (TZO) in a wide range (0–18 at.%) have been grown by reactive co-sputtering on silicon and glass substrates. The influence of the titanium incorporation in the ZnO matrix on the structural and optical characteristics of the samples has been determined by Rutherford backscattering spectroscopy (RBS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The results indicate that the samples with low Ti content (<4 at.%) exhibit a wurtzite-like structure, with the Ti4+ ions substitutionally incorporated into the ZnO structure, forming Ti-doped ZnO films. In particular, a very low concentration of Ti (<0.9 at.%) leads to a significant increase of the crystallinity of the TZO samples. Higher Ti contents give rise to a progressive amorphization of the wurtzite-like structure, so samples with high Ti content (≥18 at.%) display an amorphous structure, indicating in the XPS analysis, a predominance of Ti–O–Zn mixed oxides. The energy gap obtained from absorption spectrophotometry increases from 3.2 eV for pure ZnO films to 3.6 eV for those with the highest Ti content. Ti incorporation in the ZnO samples <0.9 at.% raises both the blue (380 nm) and green (approx. 550 nm) bands of the photoluminescence (PL) emission, thereby indicating a significant improvement of the PL efficiency of the samples.

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