Low-Energy Electron Diffraction, X-ray Photoelectron Spectroscopy, and CO-Temperature-Programmed Desorption Characterization of Bimetallic Ruthenium−Platinum Surfaces Prepared by Chemical Vapor Deposition

2001 ◽  
Vol 105 (26) ◽  
pp. 6172-6177 ◽  
Author(s):  
Abbas Lamouri ◽  
Yosi Gofer ◽  
Yu Luo ◽  
Gary S. Chottiner ◽  
Daniel A. Scherson
Keyword(s):  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Temperature Programmed Desorption ◽  
X Ray ◽  
Low Energy Electron Diffraction ◽  
Platinum Surfaces ◽  
Low Energy Electron ◽  
Temperature Programmed

Adsorption and Reaction of TiCl4 on W(100)

1993 ◽  
Vol 334 ◽  
Author(s):  
Wei Chen ◽  
Jeffrey T. Roberts
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Titanium Tetrachloride ◽  
Bound State ◽  
Temperature Programmed Desorption ◽  
X Ray ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron ◽  
Temperature Programmed

AbstractThe adsorption and reaction of titanium tetrachloride (TiC14) on W(100) was investigated using temperature programmed desorption mass spectrometry (TPRS), x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), and low energy electron diffraction (LEED). TiC14 adsorbs molecularly on W(100) at 100 K. Desorption from the molecularly bound state occurs near 220 K. Competing with desorption is dissociation to adsorbed TiCl3, which reacts to form gaseous TiCl4 near 450 K. TiC13 also decomposes into atomically adsorbed Ti and Cl on the surface upon heating to 700 K.

Laser-Assisted Deposition of Fe and W: Photodecomposition of Fe(CO)5, and W(CO)6 on Si(111)-(7×7)

1987 ◽  
Vol 101 ◽  
Author(s):  
Jon R. Swanson ◽  
C.M. Friend ◽  
Y.J. Chabal
Keyword(s):  
Vapor Deposition ◽  
Electronic Excitation ◽  
Chemical Vapor ◽  
Temperature Programmed Desorption ◽  
Observable Effect ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron ◽  
Temperature Programmed ◽  
Molecular Desorption ◽  
Initial Results

ABSTRACTThe laser-assisted chemical vapor deposition (LCVD) of Fe and W on Si(lll)-(7×7) was investigated under ultrahigh vacuum conditions at 120 K. Multiple internal reflection Fourier transform infrared and Auger electron spectroscopies and temperature programmed desorption and low energy electron diffraction were used to study the adsorption and decomposition of Fe(C0)5 and w(C0)6 on the surface. Neither of the molecules thermally reacts in temperature programmed desorption experiments. Reversible molecular desorption is exclusively observed. Decomposition of both molecules via electronic excitation was induced by ultraviolet, but not visible photons. This was shown by measuring the photodecomposition yield as a function of wavelength. Visible photolysis (λ=720 nm) had no observable effect on either molecule. No surface stable, partially decarbonylated, Fe(C0), x<5, fragments observable with infrared spectroscopy were produced by photolysis. Also, no new features were observed in temperature programmed desorption experiments and only iron was detected on the surface after photolysis. In contrast, initial results indicate that photolysis of W(C0)fi does produce surface stable, W(C0), x<6, fragments.

Interactions of Ge Atoms with High- ê Oxide Dielectric Surfaces

2005 ◽  
Vol 879 ◽  
Author(s):  
Scott K. Stanley ◽  
John G. Ekerdt
Keyword(s):  
Oxide Layer ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Temperature Programmed Desorption ◽  
Tungsten Filament ◽  
X Ray ◽  
Dielectric Surfaces ◽  
Temperature Programmed ◽  
The Stability ◽  
Ge Nanocrystals

AbstractGe is deposited on HfO2 surfaces by chemical vapor deposition (CVD) with GeH4. 0.7-1.0 ML GeHx (x = 0-3) is deposited by thermally cracking GeH4 on a hot tungsten filament. Ge oxidation and bonding are studied at 300-1000 K with X-ray photoelectron spectroscopy (XPS). Ge, GeH, GeO, and GeO2 desorption are measured with temperature programmed desorption (TPD) at 400-1000 K. Ge initially reacts with the dielectric forming an oxide layer followed by Ge deposition and formation of nanocrystals in CVD at 870 K. 0.7-1.0 ML GeHx deposited by cracking rapidly forms a contacting oxide layer on HfO2 that is stable from 300-800 K. Ge is fully removed from the HfO2 surface after annealing to 1000 K. These results help explain the stability of Ge nanocrystals in contact with HfO2.

Photoelectron spectroscopy study of amorphous silicon-carbon alloys deposited by plasma-enhanced chemical vapor deposition

1996 ◽  
Vol 11 (12) ◽  
pp. 3017-3023 ◽  
Author(s):  
G. Cicala ◽  
G. Bruno ◽  
P. Capezzuto ◽  
P. Favia
Keyword(s):  
Amorphous Silicon ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Optical Transmission ◽  
Chemical Vapor ◽  
Spectroscopy Study ◽  
Air Oxidation ◽  
X Ray ◽  
Silicon Carbon

X-ray photoelectron spectroscopy (XPS) coupled with Fourier transform infrared (FTIR) and optical transmission spectroscopy (OTS) has been used for the characterization of silicon-carbon alloys (a-Si1−xCx: H, F) deposited via plasma, by varying the CH4 amount in SiF4–CH4–H2 feeding mixture. XPS measurements have shown that carbon-rich a-Si1−xCx: H, F alloys include large amounts of fluorine (>11 at. %), which make the films susceptible to the air oxidation. In addition, the effect of the alloying partner carbon on the valence band (VB) and on the VB edge position of amorphous silicon is also described.

Chemisorption Geometry, Vibrational Spectra, and Thermal Desorption of Formic Acid on TiO2(110)

1998 ◽  
Vol 05 (01) ◽  
pp. 381-385 ◽  
Author(s):  
S. A. Chambers ◽  
M. A. Henderson ◽  
Y. J. Kim ◽  
S. Thevuthasan
Keyword(s):  
Formic Acid ◽  
Photoelectron Spectroscopy ◽  
High Energy ◽  
Decomposition Products ◽  
X Ray ◽  
Low Energy Electron Diffraction ◽  
Resolution Electron ◽  
Low Energy Electron ◽  
Temperature Programmed ◽  
Electron Energy Loss

We have used high-energy X-ray photoelectron spectroscopy and diffraction (XPS/XPD), low-energy electron diffraction (LEED), high-resolution electron energy loss spectroscopy (HREELS) and temperature-programmed desorption (TPD) to determine the molecular orientation, long-range order, vibrational frequencies, and desorption temperatures for formic acid and its decomposition products on TiO 2(110). Molecular adsorption occurs at coverages approaching one monolayer, producing a weakly ordered (2 × 1) surface structure. High-energy XPD reveals that the formate binds rigidly in a bidentate fashion through the oxygens to Ti cation rows along the [001] direction with an O–C–O bond angle of 126 ± 4°. During TPD some surface protons and formate anions recombine and desorb as formic acid above 250 K. However, most of the decomposition products follow reaction pathways leading to H 2 O , CO and H 2 CO desorption. Water is formed in TPD below 500 K via the abstraction of lattice oxygen by deposited acid protons.

Synthesis and characterization of B–C–N compounds on molybdenum

1999 ◽  
Vol 14 (3) ◽  
pp. 1137-1141 ◽  
Author(s):  
Jie Yu ◽  
E. G. Wang ◽  
Guichang Xu
Keyword(s):  
Substrate Temperature ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Synthesis And Characterization ◽  
Boron Carbonitride ◽  
X Ray ◽  
Hot Filament ◽  
N Compounds

B–C–N compounds were prepared on molybdenum by means of bias-assisted hot filament chemical vapor deposition (HFCVD). Effect of the substrate temperature (Ts) on the growth of B–C–N films has been investigated systematically by x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) based on the detailed analysis and calculation of the XPS. The substrate temperature plays a key role in the formation of the bonding states, the composition, and the surface morphology. Boron carbonitride is the main phase at all depositing temperatures, and the obtained compounds are as follows: B0.83C0.17 + B0.39C0.35N0.26 at 873 K, B0.30C0.34N0.36 at 973 K, B0.64C0.36 + B0.51C0.23N0.26 at 1073 K, B0.51C0.31N0.18 at 1173 K, and B0.37C0.54N0.09 at 1273 K.

Growth of Single Crystalline ZnO Nanotubes and Nanosquids

2007 ◽  
Vol 1057 ◽  
Author(s):  
Abhishek Prasad ◽  
Samuel Mensah ◽  
Jiesheng Wang ◽  
Archana Pandey ◽  
Yoke Khin Yap
Keyword(s):  
Vapor Deposition ◽  
Self Assembly ◽  
Chemical Vapor ◽  
Zno Nanostructures ◽  
X Ray ◽  
Thermal Chemical Vapor Deposition ◽  
Crystal Growth Mechanism ◽  
Zno Nanotubes ◽  
Solid Crystal

ABSTRACTThe growth of ZnO nanotubes and nanosquids is obtained by conventional thermal chemical vapor deposition (CVD) without the use of catalysts or templates. Characterization of these ZnO nanostructures was conducted by X-ray powder diffraction (XRD), Field-emission scanning electron microscopy (FESEM), Raman spectroscopy, and photoluminescence (PL). Results indicate that these ZnO nanostructures maintain the crystalline structures of the bulk wurtzite ZnO crystals. Our results show that rapid cooling can be used to induce the formation of ZnO nanotubes and ZnO nanosquids. The self-assembly of these novel ZnO nanostructures are guided by the theory of nucleation and the vapor-solid crystal growth mechanism.

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