Investigation of the effect of in situ annealing of FePt nanodots under high vacuum on the chemical states of Fe and Pt by x-ray photoelectron spectroscopy

2008 ◽  
Vol 104 (7) ◽  
pp. 074316 ◽  
Author(s):  
M. Murugesan ◽  
J. C. Bea ◽  
C.-K. Yin ◽  
H. Nohira ◽  
E. Ikenaga ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Vacuum ◽  
X Ray ◽  
Chemical States

Incorporation and Role of Nitrogen During Oxynitridation of Silicon Studied by Photoelectron Spectroscopy

1999 ◽  
Vol 567 ◽  
Author(s):  
Masayuki Suzuki ◽  
Yoji Saito
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Vacuum ◽  
Oxide Films ◽  
Silicon Surfaces ◽  
Gaseous Mixtures ◽  
X Ray ◽  
Initial Stage ◽  
Thermal Stability Of

ABSTRACTWe tried direct oxynitridation of silicon surfaces by remote-plasma-exited nitrogen and oxygen gaseous mixtures at 700°C in a high vacuum. The oxynitrided surfaces were investigated with in-situ X-ray photoelectron spectroscopy. With increase of the oxynitridation time, the surface density of nitrogen gradually increases, but that of oxygen shows nearly saturation behavior after the rapid increase in the initial stage. We also annealed the grown oxynitride and oxide films to investigate the role of the contained nitrogen. The desorption rate of oxygen from the oxynitride films is much less than that from oxide films. We confirmed that nitrogen stabilizes the thermal stability of these oxynitride films.

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.

Pt coated Cr2O3 thin films for resistive gas sensors

Open Physics ◽  
2009 ◽  
Vol 7 (2) ◽  
Author(s):  
Aarne Kasikov ◽  
Alar Gerst ◽  
Arvo Kikas ◽  
Leonard Matisen ◽  
Agu Saar ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Photoelectron Spectroscopy ◽  
Vacuum Annealing ◽  
High Vacuum ◽  
Atomic Layer ◽  
Electron Beam Evaporation ◽  
X Ray ◽  
Chemical States ◽  
Gas Measurements ◽  
Resistive Gas Sensors

AbstractThe resistive response of atomic layer deposited thin epitaxial α-Cr2O3(0 0 1) films, to H2 and CO in air, was studied. The films were covered with Pt nanoislands formed by electron-beam evaporation of a sub-monolayer amount of the material. The gas measurements were performed at 250°C and 450°C. These temperatures led to different proportion of chemical states, Pt2+ and Pt4+, to which the Pt oxidized. The modification was ascertained by the X-ray photoelectron spectroscopy method. As a result of the modification, the response was fast at 250°C, but slowed at 450°C. A disadvantageous abundance of Pt4+ arising at 450°C in air could be diminished by high-vacuum annealing thus restoring the response properties of the system at 250°C.

Electron induced surface reactions of (η5-C5H5)Fe(CO)2Mn(CO)5, a potential heterobimetallic precursor for focused electron beam induced deposition (FEBID)

2018 ◽  
Vol 20 (11) ◽  
pp. 7862-7874 ◽  
Author(s):  
Ilyas Unlu ◽  
Julie A. Spencer ◽  
Kelsea R. Johnson ◽  
Rachel M. Thorman ◽  
Oddur Ingólfsson ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Electron Beam ◽  
Photoelectron Spectroscopy ◽  
Surface Reactions ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
X Ray ◽  
Electron Beam Induced Deposition

Electron-induced surface reactions of (η5-C5H5)Fe(CO)2Mn(CO)5were exploredin situunder ultra-high vacuum conditions using X-ray photoelectron spectroscopy and mass spectrometry.

UHV Preparation and In-Situ Surface Analysis of MNFE/Nife Exchange Structures: Interfacial Impurity Incorporation

1993 ◽  
Vol 313 ◽  
Author(s):  
Susan L. Cohen ◽  
John M. Baker ◽  
Michael A. Russak ◽  
Gerald J. Scilla ◽  
Cherngye Hwang ◽  
...  
Keyword(s):  
Surface Analysis ◽  
Photoelectron Spectroscopy ◽  
Exchange Coupling ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Impurity Incorporation ◽  
X Ray ◽  
Manufacturing Applications ◽  
Analysis System

ABSTRACTMnFe/NiFe exchange structures have been prepared in an ultra-high vacuum sputtering/surface analysis system. Controlled introduction of residual gas impurities such as O2 and H2O at the MnFe/NiFe interface is studied by in-situ x-ray photoelectron spectroscopy (XPS) and the exchange structures are magnetically characterized. Due to the extreme reactivity of the NiFe surface towards O2, the exchange coupling is severely degraded by only small exposures of this molecule to the NiFe surface. In contrast, H2O does not oxidize the NiFe surface and therefore can be tolerated in greater quantities in the sputtering chamber without detrimental loss of exchange. This understanding of the basic surface chemistry of the MnFe and NiFe surfaces can lead to improved sputtering practices in actual manufacturing applications.

scholarly journals Recent Progress with In Situ Characterization of Interfacial Structures under a Solid–Gas Atmosphere by HP-STM and AP-XPS

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3674 ◽  
Author(s):  
Zhang ◽  
Sun ◽  
Shen ◽  
Hu ◽  
Hu ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
High Vacuum ◽  
Catalytic Reactions ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
X Ray ◽  
Heterogeneous Catalytic

: Surface science is an interdisciplinary field involving various subjects such as physics, chemistry, materials, biology and so on, and it plays an increasingly momentous role in both fundamental research and industrial applications. Despite the encouraging progress in characterizing surface/interface nanostructures with atomic and orbital precision under ultra-high-vacuum (UHV) conditions, investigating in situ reactions/processes occurring at the surface/interface under operando conditions becomes a crucial challenge in the field of surface catalysis and surface electrochemistry. Promoted by such pressing demands, high-pressure scanning tunneling microscopy (HP-STM) and ambient pressure X-ray photoelectron spectroscopy (AP-XPS), for example, have been designed to conduct measurements under operando conditions on the basis of conventional scanning tunneling microscopy (STM) and photoemission spectroscopy, which are proving to become powerful techniques to study various heterogeneous catalytic reactions on the surface. This report reviews the development of HP-STM and AP-XPS facilities and the application of HP-STM and AP-XPS on fine investigations of heterogeneous catalytic reactions via evolutions of both surface morphology and electronic structures, including dehydrogenation, CO oxidation on metal-based substrates, and so on. In the end, a perspective is also given regarding the combination of in situ X-ray photoelectron spectroscopy (XPS) and STM towards the identification of the structure–performance relationship.

XPS, AES and Leed Studies of The Interaction Between The Si(100) 2×1 Surface and Cadmium Deposited at Room Temperature

1995 ◽  
Vol 382 ◽  
Author(s):  
S. Santucci ◽  
S. Di Nardo ◽  
L. Lozzi ◽  
M. Passacantando ◽  
P. Picozzi
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Early Stage ◽  
High Vacuum ◽  
Amorphous Structure ◽  
Ultra High Vacuum ◽  
Energy Position ◽  
X Ray

ABSTRACTVery thin films of cadmium, with a mean thickness between 1 Å and 500 Å, were deposited by thermal evaporation in ultra-high-vacuum on a Si(100) 2×1 surface held at room temperature. In situ X-ray Photoelectron Spectroscopy and Auger Electron Spectroscopy were performed in order to investigate the interaction between the silicon substrate and the deposited cadmium. In samples with deposited mean thickness up to 3 Å, cadmium and silicon are found to be strongly interacting. In fact both XPS and AES spectra show evident changes in shape and energy position leading to the conclusion that a chemical compound between Cd and Si is formed. No diffusion between cadmium and silicon is observed, so the cadmium atoms deposited after the first 3 Å show a bulk character. The analysis of the first derivative intensity of the Si L23VV and Cd M5N45N45 Auger signals, varying the amount of deposited Cd, indicates the formation of islands in the early stage of the Cd growth. These islands show an amorphous structure as observed by using the LEED spectroscopy.

Low Temperature Film Growth by Supersonic Jets of CBr4

1995 ◽  
Vol 388 ◽  
Author(s):  
Douglas A. A. Ohlberg ◽  
Garry Rose ◽  
James Ren ◽  
R. Stanley Williams
Keyword(s):  
Photoelectron Spectroscopy ◽  
Film Growth ◽  
Surface Composition ◽  
Bulk Composition ◽  
High Vacuum ◽  
Depth Profiling ◽  
Deposition Efficiency ◽  
Supersonic Jets ◽  
X Ray

AbstractPulsed, supersonic jets of CBr4 seeded in a hydrogen bath gas have been used to deposit films on silicon at low temperatures (c A. 100° C) in a high vacuum chamber. IN situ analysis of the films using x-ray photoelectron spectroscopy (XPS) and depth profiling indicate a surface composition of 34% Br and 66 % C and a bulk composition of 88% C and 12% Br. the deposition efficiency of CBr4 was found to drop dramatically when seeded in bath gases of deuterium, helium, and argon, suggesting that the film growth is an activated process, requiring precursor energies of at least 3.6 eV.

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