Comparison of the Hafnium Diboride(0001) and Hafnium(0001) Surfaces

1996 ◽  
Vol 441 ◽  
Author(s):  
M. Belyansky ◽  
M. Trenary ◽  
S. Otani ◽  
T. Tanaka
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Crystal Surface ◽  
Epitaxial Thin Films ◽  
Single Crystal Surface ◽  
X Ray Diffraction ◽  
Hafnium Diboride ◽  
X Ray ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron

AbstractThe surface properties of the (0001) surfaces of single crystals of hafnium and hafnium diboride are compared with a boride film deposited on the Hf(0001) surface. The surfaces were characterized with X-ray photoelectron spectroscopy (XPS) and low energy electron diffraction (LEED). Boron deposition was achieved through the thermal decomposition of diborane. The deposited boron reacts with the hafnium substrate to form HfB2 as determined by XPS and the HfB2 films were found to be epitaxial as determined by LEED. The epitaxial nature of the thin films was confirmed with X-ray diffraction. The epitaxial thin films of HfB2 on Hf(0001) display properties identical to those of the HfB2(0001) single crystal surface.

Photoelectron spectroscopy, and low energy electron diffraction studies of the adsorption of dinitrogen, hydrogen and ammonia on a Fe(111) single crystal surface

1977 ◽  
Vol 356 (1684) ◽  
pp. 25-36 ◽  
Keyword(s):  
Electron Diffraction ◽  
Single Crystal ◽  
Photoelectron Spectroscopy ◽  
Crystal Surface ◽  
Nitride Layer ◽  
Low Energy ◽  
Energy Electron ◽  
Single Crystal Surface ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron

The chemisorption of dinitrogen, ammonia and hydrogen on the Fe (111) single crystal surface has been studied by low energy electron diffraction and high - and low - energy photoelectron spectroscopy. The clean surface is shown to be unreconstructed. Dinitrogen is chemisorbed with a low sticking probability of ca . 1 x 10 -7 at 420 K and 2 x 10 -7 at 470 K and an activation energy of ca . 20 kJ mol -1 ; evidence is presented that dinitrogen is completely dissociated at the surface. The ‘nitride’ layer shows no reaction when exposed to hydrogen at pressures of up to 10 -5 torr and temperatures up to 650 K. The chemisorption régime of ammonia is a mixed one: extensive dehydrogenation occurs at low coverage with associative sorption at higher coverage. Studies of the effects of preadsorption of hydrogen on the chemisorption of ammonia are summarized.

Van Der Waals Epitaxy of GaSe on WSe2

1992 ◽  
Vol 263 ◽  
Author(s):  
O. Lang ◽  
R. Schlaf ◽  
Y. Tomm ◽  
C. Pettenkofer ◽  
W. Jaegermann
Keyword(s):  
Electron Diffraction ◽  
Photoelectron Spectroscopy ◽  
Van Der Waals ◽  
Low Energy ◽  
Scanning Tunneling ◽  
X Ray Diffraction ◽  
Tunneling Microscopy ◽  
X Ray ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron

ABSTRACTGaSe layers were grown on the van der Waals (0001) planes of WSe2 (van der Waals epitaxy). The substrate (0001) plane was cleaned in UHV by heating to 400°C. GaSe was deposited from resistively heated Knudsen cells at T=300° C. After annealing at 450°C an epitaxial GaSe overlayer is formed as evidenced by X-ray diffraction, scanning tunneling microscopy, low energy electron diffraction and photoelectron spectroscopy.

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 Reactive Dual Magnetron Sputtering: A Fast Method for Preparing Stoichiometric Microcrystalline ZnWO4 Thin Films

Surfaces ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 106-114
Author(s):  
Yannick Hermans ◽  
Faraz Mehmood ◽  
Kerstin Lakus-Wollny ◽  
Jan P. Hofmann ◽  
Thomas Mayer ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Fast Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Post Annealing ◽  
Rf Signal ◽  
First Time

Thin films of ZnWO4, a promising photocatalytic and scintillator material, were deposited for the first time using a reactive dual magnetron sputtering procedure. A ZnO target was operated using an RF signal, and a W target was operated using a DC signal. The power on the ZnO target was changed so that it would match the sputtering rate of the W target operated at 25 W. The effects of the process parameters were characterized using optical spectroscopy, X-ray diffraction, and scanning electron microscopy, including energy dispersive X-ray spectroscopy as well as X-ray photoelectron spectroscopy. It was found that stoichiometric microcrystalline ZnWO4 thin films could be obtained, by operating the ZnO target during the sputtering procedure at a power of 55 W and by post-annealing the resulting thin films for at least 10 h at 600 °C. As FTO coated glass substrates were used, annealing led as well to the incorporation of Na, resulting in n+ doped ZnWO4 thin films.

Optical properties of anatase TiO2 films modified by N ion implantation

2012 ◽  
Vol 90 (1) ◽  
pp. 39-43 ◽  
Author(s):  
X. Xiang ◽  
D. Chang ◽  
Y. Jiang ◽  
C.M. Liu ◽  
X.T. Zu
Keyword(s):  
Thin Films ◽  
Ion Implantation ◽  
Photoelectron Spectroscopy ◽  
Radio Frequency Magnetron Sputtering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Force ◽  
Light Region ◽  
Uv Visible ◽  
Substrate Temperatures

Anatase TiO2 thin films are deposited on K9 glass samples at different substrate temperatures by radio frequency magnetron sputtering. N ion implantation is performed in the as-deposited TiO2 thin films at ion fluences of 5 × 1016, 1 × 1017, and 5 × 1017 ions/cm2. X-ray diffraction, atomic force microscope, X-ray photoelectron spectroscopy (XPS), and UV–visible spectrophotometer are used to characterize the films. With increasing N ion fluences, the absorption edges of anatase TiO2 films shift to longer wavelengths and the absorbance increases in the visible light region. XPS results show that the red shift of TiO2 films is due to the formation of N–Ti–O compounds. As a result, photoactivity is enhanced with increasing N ion fluence.

Surface Band Structure Studies of Si Rich Reconstructions on 4H-SiC(1-100)

2005 ◽  
Vol 483-485 ◽  
pp. 547-550 ◽  
Author(s):  
Konstantin V. Emtsev ◽  
Thomas Seyller ◽  
Lothar Ley ◽  
A. Tadich ◽  
L. Broekman ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Electron Diffraction ◽  
Photoelectron Spectroscopy ◽  
Low Energy ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Surface Band ◽  
X Ray ◽  
Low Energy Electron Diffraction ◽  
Different Temperatures ◽  
Low Energy Electron

We have investigated Si-rich reconstructions of 4H-SiC( 00 1 1 ) surfaces by means of low-energy electron diffraction (LEED), x-ray photoelectron spectroscopy (XPS), and angleresolved ultraviolet photoelectron spectroscopy (ARUPS). The reconstructions of 4H-SiC( 00 1 1 ) were prepared by annealing the sample at different temperatures in a flux of Si. Depending on the temperature different reconstructions were observed: c(2×2) at T=800°C, c(2×4) at T=840°C. Both reconstructions show strong similarities in the electronic structure.

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