Ex Situ and In Situ Methods for Complete Oxygen and Non-Carbidic Carbon Removal from (0001)SI 6H-SiC Surfaces

1996 ◽  
Vol 423 ◽  
Author(s):  
Sean W. King ◽  
Mark C. Benjamin ◽  
Richard S. Kern ◽  
Robert J. Nemanich ◽  
Robert F. Davis
Keyword(s):  
Ex Situ ◽  
Carbon Removal ◽  
Capping Layer ◽  
In Situ Methods ◽  
Acids And Bases

AbstractComparisons between the wetting characteristics of (0001)si 6H-SiC and (111) Si surfaces in various acids and bases were made. It was found that 10:1 HF dipped Si (111) surfaces were hydrophobic where as the (0001)si 6H-SiC surfaces were hydrophilic. (0001)si 6H-SiC surfaces capped with a 20Å Si layer, however, were hydrophobic after HF dipping and exhibited outgassing levels on annealing which were several orders of magnitude lower than SiC wafers dipped in HF without the capping layer. Annealing the Si capped (0001)si 6H-SiC surfaces in UHV at 1100°C for 5 min. was found to be sufficient to thermally desorb the Si capping layer and produce a (3×3) Si rich, oxygen free (0001)si 6H-SiC surface.

Ex Situ and in Situ Methods for Oxide and Carbon Removal from AlN and GaN Surfaces

1995 ◽  
Vol 395 ◽  
Author(s):  
Sean W. King ◽  
Laura L. Smith ◽  
John P. Barnak ◽  
Ja-Hum Ku ◽  
Jim A. Christman ◽  
...  
Keyword(s):  
Thermal Desorption ◽  
Hydrogen Plasma ◽  
Surface Oxide ◽  
Ex Situ ◽  
Plasma Exposure ◽  
Free Surfaces ◽  
In Situ Methods ◽  
Acids And Bases ◽  
Oxidation In Air

ABSTRACTExposure to numerous acids and bases and UV/O3 oxidation were used to determine the best ex situ cleaning techniques for the (0001) surfaces of AIN and GaN. HF and HCI were the most effective in removing the oxide from AIN and GaN, respectively. However, AES and XPS revealed the surfaces to be terminated with F and CI which inhibited re-oxidation prior to loading into vacuum. TPD showed mat temperatures of 650 and 850°C are necessary to thermally desorb the CI and F, respectively. UV/O3 oxidation in air was not effective in removing hydrocarbons from either surface but was effective for oxide growth. In situ remote hydrogen plasma exposure at 450°C removed halogens and hydrocarbons remaining after ex situ cleaning of both AIN and GaN surfaces; however, oxide free surfaces could not be achieved. Thermal desorption of hydrocarbons from GaN in UHV was achieved at 650°C. Complete thermal desorption of the surface oxide in UHV was only achieved at temperatures > 800°C where some GaN decomposition occurred. Annealing GaN in NH3 at 700°C reduced the surface oxide without loss of surface stoichiometry.

scholarly journals In-situ study of the corrosion process of biodegradable magnesium alloys

2021 ◽  
pp. 18-25
Author(s):  
P. N. Myagkikh ◽  
◽  
E. D. Merson ◽  
V. A. Poluyanov ◽  
D. L. Merson ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Magnesium Alloys ◽  
Human Body ◽  
Corrosion Damage ◽  
Az31 Alloy ◽  
Corrosion Process ◽  
Ex Situ ◽  
Zk60 Alloy ◽  
In Situ Methods

The interest in magnesium and its alloys considerably increases in recent years. These materials have a unique complex of properties: light-weight and strength make magnesium alloys promising structural materials for the aircraft industry and space application, and ability to reabsorb in vivo conditions and good biocompatibility allow producing biodegradable surgical implants of magnesium alloys, which can resorb in a human body without detriment to health. The materials for such demanding applications require detailed investigation of their properties, such as corrosion, including the kinetics of corrosion rate and staging of corrosion damage on the surface. To obtain a full view of the corrosion process, in addition to common ex-situ methods such as the corrosion rate evaluating using the weight loss method and the morphology corrosion damage investigation by optical or confocal laser scanning microscopy (CLSM), it is important to use modern in-situ methods. In-situ methods allow obtaining data immediately during the experiment and not after its completion. The authors carried out a comprehensive study of the corrosion process of the commercial ZK60 and AZ31 magnesium alloys in the simulated human-body environment (temperature, corrosion media composition, circulation of corrosion media) using in-situ methods, including hydrogen evolution corrosion rate evaluating and video-observation of a sample surface. The results show that AZ31 alloy is more corrosion-resistant than ZK60 alloy. Moreover, AZ31 alloy is prone to filiform surface corrosion, and ZK60 alloy exhibits severe pitting corrosion. Based on the comparison of the data obtained by in-situ and ex-situ methods, the authors concluded on their main differences and features.

Fruit wrapping kraft coated paper promotes the isolation of actinobacteria using ex situ and in situ methods

2021 ◽  
Author(s):  
Faezeh Almasi ◽  
Maghsoud Kafshnouchi ◽  
Fatemeh Mohammadipanah ◽  
Javad Hamedi
Keyword(s):  
Ex Situ ◽  
Coated Paper ◽  
In Situ Methods

The synthesis of Ru/CNF colloidal catalysts: Comparison of ex-situ and in-situ methods

2017 ◽  
Vol 4 (11) ◽  
pp. 11364-11370 ◽  
Author(s):  
Yuliya S. Demidova ◽  
Irina L. Simakova ◽  
Tim Schubert ◽  
Dmitry Yu. Murzin
Keyword(s):  
Ex Situ ◽  
In Situ Methods

scholarly journals Conservation of Rare Plants Using “Ex Situ“ And ”In Situ” Methods in Coal Industry Objects Designing

2018 ◽  
Vol 41 ◽  
pp. 02009
Author(s):  
Oleg Kupriyanov ◽  
Tatyana Strelnikova
Keyword(s):  
Natural Habitat ◽  
Botanical Garden ◽  
Coal Industry ◽  
Rare Plants ◽  
Ex Situ ◽  
Open Pit ◽  
Plant Populations ◽  
Industrial Enterprises ◽  
In Situ Methods

The experience of predesign inspection of the territory put under impact of future open pit is observed in the article. Geobotanical researches were carried out and populations of two plant species included in the Red Book of the Kemerovo region were found: Glycyrrhiza uralensis Fischer and Epipactis helleborine (L.) Grantz. Conservation of G. uralensis was carried out by “in situ” method – by transfer on other natural habitat. Individuals of E. helleborine were transferred at the territory of the Kuzbass botanical garden. Two years' observations of populations’ condition have shown successful growth of all individuals. These methods of conservation of rare plant populations are recommended by Project of UNDP-GEF for implementation at the industrial enterprises.

Comparative study of erbium disilicide thin films grown in situ under ultrahigh vacuum or ex situ with a capping layer

2012 ◽  
Vol 520 (13) ◽  
pp. 4501-4505 ◽  
Author(s):  
N. Reckinger ◽  
C.A. Duţu ◽  
X. Tang ◽  
E. Dubois ◽  
D.A. Yarekha ◽  
...  
Keyword(s):  
Thin Films ◽  
Comparative Study ◽  
Ultrahigh Vacuum ◽  
Ex Situ ◽  
Capping Layer

Systematic studies of SiGe/Si islands nucleated via separate in situ, or ex situ, Ga+ focused ion beam-guided growth techniques

2003 ◽  
Vol 794 ◽  
Author(s):  
T. E. Vandervelde ◽  
S. Atha ◽  
T. L. Pernell ◽  
R. Hull ◽  
J.C. Bean
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Ex Situ ◽  
Surface Roughening ◽  
Guided Growth ◽  
Island Nucleation ◽  
Capping Layer ◽  
Doping Effects ◽  
Higher Doses

ABSTRACTIn this study we use 25keV in situ and 30keV ex situ Ga+ focused ion beams (FIB) to locally modify the substrate before deposition to determine its affect on nucleation of MBE-grown Ge/Si islands. FIB processing may alter island formation in at least four ways: the surfactant effect of Ga+, doping effects of subsurface Ga+, crystalline damage, and surface roughening. To explore these possibilities, we milled square regions of increasing Ga+ doses and used AFM to monitor islanding in and around these regions. For in situ experiments, doses ranged from ∼1013 to 5×1017ions/cm2. We began to observe changes in island topology at doses as low as ∼1014ions/cm2. For doses of ∼1015ions/cm2 to ∼8×1016ions/cm2, implanted areas were surrounded by denuded zones that grew from ∼0.5 to 6 μm. Immediately inside the implanted area, island concentration (size and density) appeared to peak. At doses above ∼6×1016ions/cm2, Ga+ produced noticeable surface depressions, which were often surrounded by enhanced island densities, rather than a denuded zone. For ex situ FIB patterning, samples underwent both pre-growth cleaning and growth of a thin capping layer. Doses ranging from 7.5×1013 to ∼1017 ions/cm2 were used with varied capping layer thicknesses to study their combined affect on island nucleation. The results correspond well with in situ experiments for thin capping layers. Increased capping layer thickness show muted modifications for low Ga+ doses, while for higher doses trends similar to the in situ results are seen.

Ex situ and in situ methods of inspecting and optimizing adaptive bimorph mirrors

2010 ◽  
Vol 1 (MEDSI-6) ◽  
Author(s):  
J. P. Sutter ◽  
S. Alcock ◽  
K. Sawhney
Keyword(s):  
Adaptive Optics ◽  
Ex Situ ◽  
Optical Metrology ◽  
X Ray ◽  
Optical Surfaces ◽  
In Situ Methods ◽  
Synchrotron Light ◽  
Reflecting Surface ◽  
Good Agreement

At the Diamond Light Source, adaptive bimorph mirrors are extensively used to focus synchrotron light. Piezo crystals embedded in each bimorph mirror expand or contract in response to applied voltages, enabling the curvature of the reflecting surface to adapt to the required form. However, high-grade metrology tools are needed to determine the optimal voltages. The Diamond Optics & Metrology group have implemented in situ (on the beamlines) and ex situ (in a metrology lab) methods of characterizing optical surfaces. For ex situ tests, a slope-measuring profiler (the Diamond-NOM (Nanometre Optical Metrology)) is employed. In situ, X-ray pencil beam scans, performed using an X-ray sensitive camera and software designed in-house, are used to correct optical slope errors. Ex situ and in situ data are shown to be in good agreement. Examples of in situ improvements in the focusing quality and deliberate defocusing are shown. The methods developed are also applicable to many other forms of adaptive optics.

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