In situ investigation of M/CuO interface (M is Ti, V, Cr or Mn) by X-ray photoelectron spectroscopy

2015 ◽  
Vol 29 (04) ◽  
pp. 1530002 ◽  
Author(s):  
A. R. Chourasia ◽  
Jacob Stahl
Keyword(s):  
Metal Oxide ◽  
Copper Oxide ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Chemical Reactivity ◽  
Spectral Features ◽  
Metallic Oxide ◽  
X Ray ◽  
Elemental Copper

The technique of X-ray photoelectron spectroscopy has been used to investigate the chemical reactivity at the metal/ CuO interfaces. Thin films of the metallic overlayer (0.5 nm, 1.0 nm and 2.0 nm thickness) were deposited on copper oxide substrates at room temperature. In situ characterization of the interfaces has been performed. The 2p core level regions of the metals have been investigated. The spectral features show considerable reactivity at the interfaces. The core level peaks of the metal are observed to be shifted to the high BE energy side with the appearance of satellites. The spectral data confirm the formation of the metallic oxide at the interface. The satellite structure in the copper region is observed to disappear and the spectral features are found to approach those of elemental copper. The room temperature deposition of the metal on copper oxide therefore results in the reduction of copper oxide to elemental copper followed by the oxidation of the metal. The interface is found to consist of a mixture of metal oxide and elemental copper. The 2.0 nm samples were annealed. These samples show the diffusion of copper oxide through the overlayer. The metal reacts with this diffusing oxide to form metallic oxide. The interface is found to consist of a mixture of unreacted metal, the metal oxide, and elemental copper. The amount of the unreacted metal varied between 0% and 40% and can be controlled by the processing conditions. The investigation shows room temperature chemical reactivity at the metal/ CuO interface and provides a new method of preparing sub-nano-oxide films.

scholarly journals Characterization of Ti/SnO2 Interface by X-ray Photoelectron Spectroscopy

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 202
Author(s):  
Miranda Martinez ◽  
Anil R. Chourasia
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Chemical Interaction ◽  
Photoelectron Spectra ◽  
X Ray ◽  
Increasing Trend ◽  
Substrate Temperatures ◽  
Beam Technique

The Ti/SnO2 interface has been investigated in situ via the technique of x-ray photoelectron spectroscopy. Thin films (in the range from 0.3 to 1.1 nm) of titanium were deposited on SnO2 substrates via the e-beam technique. The deposition was carried out at two different substrate temperatures, namely room temperature and 200 °C. The photoelectron spectra of tin and titanium in the samples were found to exhibit significant differences upon comparison with the corresponding elemental and the oxide spectra. These changes result from chemical interaction between SnO2 and the titanium overlayer at the interface. The SnO2 was observed to be reduced to elemental tin while the titanium overlayer was observed to become oxidized. Complete reduction of SnO2 to elemental tin did not occur even for the lowest thickness of the titanium overlayer. The interfaces in both the types of the samples were observed to consist of elemental Sn, SnO2, elemental titanium, TiO2, and Ti-suboxide. The relative percentages of the constituents at the interface have been estimated by curve fitting the spectral data with the corresponding elemental and the oxide spectra. In the 200 °C samples, thermal diffusion of the titanium overlayer was observed. This resulted in the complete oxidation of the titanium overlayer to TiO2 upto a thickness of 0.9 nm of the overlayer. Elemental titanium resulting from the unreacted overlayer was observed to be more in the room temperature samples. The room temperature samples showed variation around 20% for the Ti-suboxide while an increasing trend was observed in the 200 °C samples.

Study of Ta as a Diffusion Barrier in Cu/SiO2 Structure

2000 ◽  
Vol 612 ◽  
Author(s):  
J. S. Pan ◽  
A. T. S. Wee ◽  
C. H. A. Huan ◽  
J. W. Chai ◽  
J. H. Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Room Temperature ◽  
Depth Profiling ◽  
Oxide Formation ◽  
X Ray ◽  
Chemical States ◽  
The Stability

AbstractTantalum (Ta) thin films of 35 nm thickness were investigated as diffusion barriers as well as adhesion-promoting layers between Cu and SiO2 using X-ray diffractometry (XRD), Scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). After annealing at 600°C for 1h in vacuum, no evidence of interdiffusion was observed. However, XPS depth profiling indicates that elemental Si appears at the Ta/SiO2 interface after annealing. In-situ XPS studies show that the Ta/SiO2 interface was stable until 500°C, but about 32% of the interfacial SiO2 was reduced to elemental Si at 600°C. Upon cooling to room temperature, some elemental Si recombined to form SiO2 again, leaving only 6.5% elemental Si. Comparative studies on the interface chemical states of Cu/SiO2 and Ta/SiO2 indicate that the stability of the Cu/Ta/SiO2/Si system may be ascribed to the strong bonding of Ta and SiO2, due to the reduction of SiO2 through Ta oxide formation.

scholarly journals Получение нанокомпозитов МУНТ/MnO-=SUB=-2-x-=/SUB=-, МУНТ/MnO-=SUB=-2-x-=/SUB=-/CuO и исследования их газочувствительных свойств

2019 ◽  
Vol 61 (11) ◽  
pp. 2240
Author(s):  
Ю.А. Стенькин ◽  
В.В. Болотов ◽  
Д.В. Соколов ◽  
В.Е. Росликов ◽  
К.Е. Ивлев
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Copper Oxide ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Gas Sensing ◽  
Multiwalled Carbon ◽  
X Ray ◽  
P Type ◽  
Scanning Electron

Nanocomposites based on multiwalled carbon nanotubes (MWCNT) with manganese dioxide (MnO2-x) and copper oxide (CuO) were obtained and investigated. The morphology and elemental composition of MWCNT-layer and nanocomposites MWCNT/MnO2-х, MWCNT/MnO2-х/CuO were studied by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The gas sensing response of MWCNT-layer and nanocomposites upon exposure to hydrogen sulfide (H2S) and nitrogen dioxide (NO2) was demonstrated at room temperature. Effect of increasing the conductivity of MWCNT-layer and nanocomposites upon exposure to NO2 indicates these nanomaterials have conductive of p-type. Copper oxide in nanocomposite significantly enhances the gas sensing response to H2S.

Importance of the Metal-Oxide Interface in Catalysis: In Situ Studies of the Water-Gas Shift Reaction by Ambient-Pressure X-ray Photoelectron Spectroscopy

2013 ◽  
Vol 125 (19) ◽  
pp. 5205-5209 ◽  
Author(s):  
Kumudu Mudiyanselage ◽  
Sanjaya D. Senanayake ◽  
Leticia Feria ◽  
Shankhamala Kundu ◽  
Ashleigh E. Baber ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
Water Gas Shift ◽  
Water Gas Shift Reaction ◽  
Oxide Interface ◽  
X Ray ◽  
Shift Reaction ◽  
Water Gas

scholarly journals Room-Temperature Reaction of Oxygen with Gold: An In situ Ambient-Pressure X-ray Photoelectron Spectroscopy Investigation

2010 ◽  
Vol 132 (9) ◽  
pp. 2858-2859 ◽  
Author(s):  
Peng Jiang ◽  
Soeren Porsgaard ◽  
Ferenc Borondics ◽  
Mariana Köber ◽  
Alfonso Caballero ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Ambient Pressure ◽  
Temperature Reaction ◽  
X Ray

Metal-Ceramic Interfacial Reactions: The Copper-Cordierite and Titanium-Cordierite Systems.

1988 ◽  
Vol 119 ◽  
Author(s):  
M. Bortz ◽  
F. S. Ohuchi
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Interfacial Reactions ◽  
Comprehensive Treatment ◽  
Interfacial Chemistry ◽  
Ceramic Substrates ◽  
Copper Diffusion ◽  
X Ray ◽  
Metal Ceramic

AbstractInterfacial reactions between either copper or titanium and cordierite-based (2MgO.2Al2O3.5SiO2) ceramic substrates are probed using X-ray Photoelectron Spectroscopy (XPS). Room temperature reactions are found to be strongly dependent on interfacial chemistry; while copper reacts weakly with the cordierite surface, titanium strongly reduces the Si-O and Al-O substrate bonds. Behavior during subsequent “in situ” annealing is dependent on substrate morphology. On amorphous cordierite films copper remains nonreactive while titanium dissociates remaining Si-O and Al-O bonds, forming a low valency Ti1+ oxide. On crystalline cordierite substrates copper diffuses rapidly upon annealing while titanium reduces substrate bonds forming a high valency Ti3+ oxide. Furthermore, thin 5Å Ti interlayers prevent copper diffusion at temperatures below 650°C. This study represents the first comprehensive treatment of the interfacial reactions in metal-multicomponent ceramic systems.

scholarly journals Epitaxial growth and structure of cobalt ferrite thin films with large inversion parameter on Ag(001)

2019 ◽  
Vol 75 (1) ◽  
pp. 8-17 ◽  
Author(s):  
Maurizio De Santis ◽  
Aude Bailly ◽  
Ian Coates ◽  
Stéphane Grenier ◽  
Olivier Heckmann ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Spinel Structure ◽  
Room Temperature ◽  
Cobalt Ferrite ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Step Method ◽  
X Ray ◽  
Octahedral Sites

Cobalt ferrite ultrathin films with the inverse spinel structure are among the best candidates for spin filtering at room temperature. High-quality epitaxial CoFe2O4 films about 4 nm thick have been fabricated on Ag(001) following a three-step method: an ultrathin metallic CoFe2 alloy was first grown in coherent epitaxy on the substrate and then treated twice with O2, first at room temperature and then during annealing. The epitaxial orientation and the surface, interface and film structure were resolved using a combination of low-energy electron diffraction, scanning tunnelling microscopy, Auger electron spectroscopy and in situ grazing-incidence X-ray diffraction. A slight tetragonal distortion was observed, which should drive the easy magnetization axis in-plane due to the large magneto-elastic coupling of such a material. The so-called inversion parameter, i.e. the Co fraction occupying octahedral sites in the ferrite spinel structure, is a key element for its spin-dependent electronic gap. It was obtained through in situ resonant X-ray diffraction measurements collected at both the Co and Fe K edges. The data analysis was performed using FDMNES, an ab initio program already extensively used to simulate X-ray absorption spectroscopy, and shows that the Co ions are predominantly located on octahedral sites with an inversion parameter of 0.88 (5). Ex situ X-ray photoelectron spectroscopy gives an estimation in accordance with the values obtained through diffraction analysis.

Importance of the Metal-Oxide Interface in Catalysis: In Situ Studies of the Water-Gas Shift Reaction by Ambient-Pressure X-ray Photoelectron Spectroscopy

2013 ◽  
Vol 52 (19) ◽  
pp. 5101-5105 ◽  
Author(s):  
Kumudu Mudiyanselage ◽  
Sanjaya D. Senanayake ◽  
Leticia Feria ◽  
Shankhamala Kundu ◽  
Ashleigh E. Baber ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
Water Gas Shift ◽  
Water Gas Shift Reaction ◽  
Oxide Interface ◽  
X Ray ◽  
Shift Reaction ◽  
Water Gas

‘In-situ’ Solution Processed Room Temperature Ferromagnetic MgO Thin Films Printed by Inkjet Technique

2011 ◽  
Vol 1292 ◽  
Author(s):  
Yan Wu ◽  
Yiqiang Zhan ◽  
Mats Fahlman ◽  
Mei Fang ◽  
K. V. Rao ◽  
...  
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Defect Structure ◽  
Room Temperature ◽  
Solution Processed ◽  
X Ray ◽  
Si Substrates ◽  
Ph Values

ABSTRACTWe report on ‘in-situ’ solution processed homogeneous (200) oriented MgO ~85nm thin films deposited on Si substrates by inkjet printing. These films are found to show ferromagnetic order beyond room temperature with a saturation magnetization MS as high as ~0.63 emu/g. X-ray photoelectron spectroscopy investigations show the absence of any possible contamination effects, while the Mg 2p, and O 1s spectra indicate that the role of defect structure at the Mg site is important in the observed magnetism. By controlling the pH values of the precursors the concentration of the defects can be varied and hence tune the magnetization at room temperature. The origin of magnetism in these MgO thin films appears to arise from the cation vacancies.

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