High Resolution Leed Study of The Fe Growth Mode on Cu(100), Cu(110) and Cu (111) Surfaces

1991 ◽  
Vol 237 ◽  
Author(s):  
Yuqun Cao ◽  
Pedro A. Montano
Keyword(s):  
High Resolution ◽  
Substrate Temperature ◽  
Epitaxial Growth ◽  
Copper Surface ◽  
Growth Mode ◽  
Diffraction Spot ◽  
Sudden Increase ◽  
Copper Surfaces ◽  
Single Crystal Surfaces ◽  
Before And After

ABSTRACTWe have investigated the growth mode of iron on clean Cu(100), Cu (110) and Cu(111) surfaces using high resolution LEED. We studied the effect of substrate temperature on the growth of epitaxial fee iron. Iron metal was evaporated from an electron beam source under UHV conditions and deposited on the copper single crystal surfaces at three different temperatures (173 K, 300 K and 473 K). A high resolution LEED system was used to measure the diffraction spot profiles. The samples were studied as a function of temperature after deposition on the copper substrates. The clean Cu surfaces were also measured and used as references for the Fe:Cu system. The diffraction spot profiles show Gaussian line shape before and after the Fe deposition. The effect of iron grown on the Cu surface is to reduce the coherent length. This effect is observed for all the copper surfaces. The intensity of the diffraction spots exhibit a sudden increase above 470 K, simultaneously a larger coherent length is observed. This effect occurs for all copper surfaces. The epitaxial growth of Fe is better on Cu (100) than on the other surfaces. The best epitaxial growth is obtained for the highest substrate temperature. A careful Auger study reveals that the anomalous increase observed on the intensity of the diffraction spots is related to the evaporation of iron from the copper surface. The spot profiles at low temperature are very broad and are suggestive of very poor epitaxy, random islands growth with a high probability of bec iron inclusions.

Evaporation of Silver-Graphene Hybrid Nanofluid Droplet on its Nanostructured Residue and Plain Copper Surfaces at Elevated Temperatures

2020 ◽  
Author(s):  
Farooq Riaz Siddiqui ◽  
Chi Yan Tso ◽  
Sau Chung Fu ◽  
Huihe Qiu ◽  
Christopher Yu Hang Chao
Keyword(s):  
Substrate Temperature ◽  
Evaporation Rate ◽  
Elevated Temperatures ◽  
Droplet Evaporation ◽  
Copper Surface ◽  
Copper Plate ◽  
Hybrid Nanofluid ◽  
Copper Surfaces ◽  
Latent Energy ◽  
Droplet Sizes

Abstract Droplet evaporation is an efficient process as it removes a large amount of heat by using the latent energy, making it suitable for heat transfer applications. In this research, evaporation of the silver-graphene hybrid nanofluid (SGHF) droplet, because of its synergistic thermal conductivity, is investigated for substrate temperature in a range of 25–100 °C. The experiments for droplet evaporation were performed in an environmental facility for two droplet sizes, 3 μL and 30 μL volume, on a copper plate. A 100 W silicone heater mat was used to heat the copper plate from the underside, while two T-type thermocouples were used to monitor its surface temperature. As droplet evaporation ended, a porous residue was formed on the copper surface. Subsequently, a 3 μL volume of the SGHF droplet was dispensed on the porous residue surface. The results showed a tremendous rise in the evaporation rate (up to 160%) for the subsequent SGHF droplet sitting on the porous residue as compared to the non-wetted copper surface. Moreover, the evaporation rate of the SGHF droplet on the copper surface increased up to 56% as compared to the water droplet for a substrate temperature range of 25–100 °C.

scholarly journals The Structure of Al/GaAs Interfaces

1986 ◽  
Vol 77 ◽  
Author(s):  
Zuzanna Liliental-Weber ◽  
C. Nelson ◽  
R. Gronsky ◽  
J. Washburn ◽  
R. Ludeke
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Molecular Beam Epitaxy ◽  
Substrate Temperature ◽  
Epitaxial Growth ◽  
Gaas Substrate ◽  
Molecular Beam ◽  
High Resolution Electron Microscopy ◽  
Resolution Electron ◽  
Molecular Beam Epitaxy Chamber

ABSTRACTThe structure of Al/GaAs interfaces was investigated by high resolution electron microscopy. The Al layers Were deposited in a molecular beam epitaxy chamber with a vacuum base pressure of <1×10∼8 Pa. The GaAs substrate temperature varied during Al deposition from -30°C to 400°C. Deposition of Al on cold substrates £25°C resulted in epitaxial growth of (001) Al on (001) GaAs. Droplets of Ga were observed in samples with the substrate temperature at -30°C (1×2) and 0°C (c(2×8)). Postannealing of the last sample caused formation of the AlGaAs phase. Deposition of Al on hot substrates (150°C and 400°C) resulted in the formation of the AlGaAs phase, which separated (110) oriented Al from (001)GaAs.

Characterization of Microcrystalline Transition from Amorphous Silicon as a Function of Hydrogen Dilution and Substrate Temperature of Hot-wire CVD

2002 ◽  
Vol 715 ◽  
Author(s):  
Keda Wang ◽  
Haoyue Zhang ◽  
Jian Zhang ◽  
Jessica M. Owens ◽  
Jennifer Weinberg-Wolf ◽  
...  
Keyword(s):  
Substrate Temperature ◽  
Sudden Change ◽  
Chemical Vapor ◽  
Threshold Value ◽  
Ir Absorption ◽  
Sudden Increase ◽  
Hot Wire ◽  
Hydrogen Dilution ◽  
Integral Absorption ◽  
Two Peaks

Abstracta-Si:H films were prepared by hot wire chemical vapor deposition. One group was deposited at a substrate temperature of Ts=250°C with varied hydrogen-dilution ratio, 0<R<10; the other group was deposited with fixed R=3 but a varied Ts from 150 to 550°C. IR, Raman and PL spectra were studied. The Raman results indicate that there is a threshold value for the microstructure transition from a- to μc-Si. The threshold is found to be R ≈ 2 at Ts = 250°C and Ts ≈ 200°C at R=3. The IR absorption of Si-H at 640 cm-1 was used to calculate the hydrogen content, CH. CH decreased monotonically when either R or Ts increased. The Si-H stretching mode contains two peaks at 2000 and 2090 cm-1. The ratio of the integral absorption peaks I2090/(I2090+I2090) showed a sudden increase at the threshold of microcrystallinity. At the same threshold, the PL features also indicate a sudden change from a- to μc-Si., i.e. the low energy PL band becomes dominant and the PL total intensity decreases. We attribute the above IR and PL changes to the contribution of microcrystallinity, especially the c-Si gain-boundaries.

scholarly journals PTU-151 High Resolution Manometry Profile of Hiatal Hernia in Patients before and after Fundoplication: Abstract PTU-151 Table

Gut ◽  
2013 ◽  
Vol 62 (Suppl 1) ◽  
pp. A109.2-A110 ◽  
Author(s):  
K Bilnik ◽  
E Klimacka-Nawrot ◽  
J Kurek ◽  
B Blonska-Fajfrowska ◽  
A Stadnicki
Keyword(s):  
High Resolution ◽  
Hiatal Hernia ◽  
High Resolution Manometry ◽  
Before And After

Structural Characterization of Epitaxial GMR Magnetic Multilayers and Spin Valves Grown by Sputter Deposition

2000 ◽  
Vol 614 ◽  
Author(s):  
H. Geng ◽  
R. Loloee ◽  
J.W. Heckman ◽  
J. Bass ◽  
W.P. Pratt ◽  
...  
Keyword(s):  
High Resolution ◽  
Epitaxial Growth ◽  
Magnetic Multilayers ◽  
Sputter Deposition ◽  
Dc Magnetron Sputtering ◽  
Cu Films ◽  
Electron Backscatter ◽  
High Resolution Tem ◽  
Fcc Structure

ABSTRACTEpitaxial Cu/Py/FeMn and (Cu/Co)×20 GMR magnetic multilayers were grown on single crystal (011) Nb that was deposited on (1121) Al2O3 substrates by dc magnetron sputtering. Electron backscatter patterns (EBSPs) revealed that the Cu films display two twin variants, corresponding to two stacking sequences of {111} planes in fcc. The epitaxial orientation relationship between the bcc Nb and both fcc Cu variants was the Nishiyama-Wasserman (N-W) relationship. Conventional TEM observations revealed epitaxial growth for both the Cu/Py/FeMn and (Cu/Co)×20 multilayers. High-resolution TEM confirmed epitaxial growth of close packed (011) Nb on (1120) Al2O3 substrates with [111]Nb∥[0001]Al2O3. Numerous small twins were observed in the Cu near the Cu-Nb interface of the Cu/Py/FeMn multilayer. In the Cu/Co multilayer, the growth planes of the Cu and Co were found to be {100} instead of the expected close-packed {111} planes of the fcc structure.

scholarly journals High-resolution Manometry in Patients with Gastroesophageal Reflux Disease Before and After Fundoplication

2017 ◽  
Vol 23 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Katarzyna Rerych ◽  
Józef Kurek ◽  
Ewa Klimacka-Nawrot ◽  
Barbara Błońska-Fajfrowska ◽  
Antoni Stadnicki
Keyword(s):  
High Resolution ◽  
Gastroesophageal Reflux Disease ◽  
Gastroesophageal Reflux ◽  
Reflux Disease ◽  
High Resolution Manometry ◽  
Before And After

Hetero-Epitaxial Growth of 3C-SiC on Silicon Substrates by Plasma Assisted CVD

2006 ◽  
Vol 527-529 ◽  
pp. 299-302
Author(s):  
Hideki Shimizu ◽  
Yosuke Aoyama
Keyword(s):  
Substrate Temperature ◽  
Single Crystal ◽  
Epitaxial Growth ◽  
Deposition Rate ◽  
Crystalline Structure ◽  
Flow Rate ◽  
Silicon Substrates ◽  
High Quality ◽  
Sic Films ◽  
Lower Substrate Temperature

3C-SiC films grown on carbonized Si (100) by plasma-assisted CVD have been investigated with systematic changes in flow rate of monosilane (SiH4) and propane (C3H8) as source gases. The deposition rate of the films increased monotonously and the microstructures of the films changed from 3C-SiC single crystal to 3C-SiC polycrystal with increasing flow rate of SiH4. Increasing C3H8 keeps single crystalline structure but results in contamination of α-W2C, which is a serious problem for the epitaxial growth. To obtain high quality 3C-SiC films, the effects of C3H8 on the microstructures of the films have been investigated by reducing the concentration of C3H8. Good quality 3C-SiC single crystal on Si (100) is grown at low net flow rate of C3H8 and SiH4, while 3C-SiC single crystal on Si (111) is grown at low net flow rate of C3H8 and high net flow rate of SiH4. It is expected that 3C-SiC epitaxial growth on Si (111) will take placed at a higher deposition rate and lower substrate temperature than that on Si (100).

scholarly journals Dynamics of Erosion and Deposition in a Partially Restored Valley-Bottom Gully

Land ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 62
Author(s):  
Alberto Alfonso-Torreño ◽  
Álvaro Gómez-Gutiérrez ◽  
Susanne Schnabel
Keyword(s):  
High Resolution ◽  
Sediment Deposition ◽  
Aerial Images ◽  
Valley Bottom ◽  
Erosion And Deposition ◽  
Channel Dynamics ◽  
Check Dams ◽  
Before And After ◽  
Multi Temporal ◽  
Spatio Temporal

Gullies are sources and reservoirs of sediments and perform as efficient transfers of runoff and sediments. In recent years, several techniques and technologies emerged to facilitate monitoring of gully dynamics at unprecedented spatial and temporal resolutions. Here we present a detailed study of a valley-bottom gully in a Mediterranean rangeland with a savannah-like vegetation cover that was partially restored in 2017. Restoration activities included check dams (gabion weirs and fascines) and livestock exclosure by fencing. The specific objectives of this work were: (1) to analyze the effectiveness of the restoration activities, (2) to study erosion and deposition dynamics before and after the restoration activities using high-resolution digital elevation models (DEMs), (3) to examine the role of micro-morphology on the observed topographic changes, and (4) to compare the current and recent channel dynamics with previous studies conducted in the same study area through different methods and spatio-temporal scales, quantifying medium-term changes. Topographic changes were estimated using multi-temporal, high-resolution DEMs produced using structure-from-motion (SfM) photogrammetry and aerial images acquired by a fixed-wing unmanned aerial vehicle (UAV). The performance of the restoration activities was satisfactory to control gully erosion. Check dams were effective favoring sediment deposition and reducing lateral bank erosion. Livestock exclosure promoted the stabilization of bank headcuts. The implemented restoration measures increased notably sediment deposition.

Epitaxial growth of the topological insulator Bi2Se3 on Si(111): Growth mode, lattice parameter, and strain state

2013 ◽  
Vol 103 (11) ◽  
pp. 111909 ◽  
Author(s):  
M. Vyshnepolsky ◽  
C. Klein ◽  
F. Klasing ◽  
A. Hanisch-Blicharski ◽  
M. Horn-von Hoegen
Keyword(s):  
Epitaxial Growth ◽  
Topological Insulator ◽  
Strain State ◽  
Lattice Parameter ◽  
Growth Mode
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