scholarly journals Room-Temperature Deposition of Cobalt Monolayer on (7×4) Crown-Ether Ring Molecular Array : Ultra-High Vacuum STM and UPS Study

2020 ◽  
Vol 63 (9) ◽  
pp. 465-469
Author(s):  
Ryohei NEMOTO ◽  
Peter KRÜGER ◽  
Takuya HOSOKAI ◽  
Masaki HORIE ◽  
Satoshi KERA ◽  
...  
Keyword(s):  
Crown Ether ◽  
Room Temperature ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Temperature Deposition

TEM sample preparation of wear-tested room-temperature pulsed-laser-deposited thin films of MoS2 by ultramicrotomy

1993 ◽  
Vol 51 ◽  
pp. 1118-1119
Author(s):  
Pamela F. Lloyd ◽  
Scott D. Walck
Keyword(s):  
Thin Films ◽  
Sample Preparation ◽  
Room Temperature ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Ultra High Vacuum ◽  
Wear Testing ◽  
Preparation Technique ◽  
Cross Sectional ◽  
Aerospace Applications

Pulsed laser deposition (PLD) is a novel technique for the deposition of tribological thin films. MoS2 is the archetypical solid lubricant material for aerospace applications. It provides a low coefficient of friction from cryogenic temperatures to about 350°C and can be used in ultra high vacuum environments. The TEM is ideally suited for studying the microstructural and tribo-chemical changes that occur during wear. The normal cross sectional TEM sample preparation method does not work well because the material’s lubricity causes the sandwich to separate. Walck et al. deposited MoS2 through a mesh mask which gave suitable results for as-deposited films, but the discontinuous nature of the film is unsuitable for wear-testing. To investigate wear-tested, room temperature (RT) PLD MoS2 films, the sample preparation technique of Heuer and Howitt was adapted.Two 300 run thick films were deposited on single crystal NaCl substrates. One was wear-tested on a ball-on-disk tribometer using a 30 gm load at 150 rpm for one minute, and subsequently coated with a heavy layer of evaporated gold.

scholarly journals Annealing Condition Effects on the Structural Properties of FePt Nanoparticles Embedded in MgO via Pulsed Laser Deposition

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 131
Author(s):  
Tingting Xiao ◽  
Qi Yang ◽  
Jian Yu ◽  
Zhengwei Xiong ◽  
Weidong Wu
Keyword(s):  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Annealing Process ◽  
Ultra High Vacuum ◽  
Laser Deposition ◽  
Fept Nanoparticles ◽  
Annealing Conditions ◽  
Vacuum Atmosphere

FePt nanoparticles (NPs) were embedded into a single-crystal MgO host by pulsed laser deposition (PLD). It was found that its phase, microstructures and physical properties were strongly dependent on annealing conditions. Annealing induced a remarkable morphology variation in order to decrease its total free energy. H2/Ar (95% Ar + 5% H2) significantly improved the L10 ordering of FePt NPs, making magnetic coercivity reach 37 KOe at room temperature. However, the samples annealing at H2/Ar, O2, and vacuum all showed the presence of iron oxide even with the coverage of MgO. MgO matrix could restrain the particles’ coalescence effectively but can hardly avoid the oxidation of Fe since it is extremely sensitive to oxygen under the high-temperature annealing process. This study demonstrated that it is essential to anneal FePt in a high-purity reducing or ultra-high vacuum atmosphere in order to eliminate the influence of oxygen.

Well-Ordered Monolayer Growth of Crown-Ether Ring Molecules on Cu(111) in Ultra-High Vacuum: An STM, UPS, and DFT Study

2019 ◽  
Vol 123 (31) ◽  
pp. 18939-18950 ◽  
Author(s):  
Ryohei Nemoto ◽  
Peter Krüger ◽  
Ayu Novita Putri Hartini ◽  
Takuya Hosokai ◽  
Masaki Horie ◽  
...  
Keyword(s):  
Crown Ether ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Dft Study ◽  
Ring Molecules ◽  
Monolayer Growth

scholarly journals The Determination of Interfacial Structure and Phase Transitions in Al/Cu and Al/Ni Interfaces by Means of Surface Extended X-Ray Absorption Fine Structure

1991 ◽  
Vol 238 ◽  
Author(s):  
E. V. Barrera ◽  
S. M. Heald
Keyword(s):  
Fine Structure ◽  
Room Temperature ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Interfacial Structure ◽  
Reaction Products ◽  
X Ray ◽  
Absorption Fine ◽  
Reaction Zones ◽  
X Ray Absorption

ABSTRACTSurface extended x-ray absorption fine structure (SEXAFS) was used to investigate the interfacial conditions of Al/Cu and Al/Ni shallow buried interfaces. Previous studies using glancing angle extended x-ray absorption fine structure, x-ray reflectivity, photoemission, and SEXAFS produced conflicting results as to whether or not the interfaces between Al and Cu and Al and Ni were reacted upon room temperature deposition. In this study polycrystalline bilayers of Al/Cu and Al/Ni and trilayers of Al/Cu/Al and Al/Ni/Al were deposited on tantalum foil at room temperature in ultra high vacuum and analyzed to evaluate the reactivity of these systems on a nanometer scale. It became overwhelming apparent that the interfacial phase reactions were a function of the vacuum conditions. Samples deposited with the optimum vacuum conditions showed reaction products upon deposition at room temperature which were characterized by comparisons to standards and by least squares fitting to be CuAl2 and NiAl3 respectively. The results of this study showed that the reacted zone thicknesses were readily dependent on the deposition parameters. For both Al on Cu and Al on Ni as well as the metal on Al conditions 10A reaction zones were observed. These reaction zones were smaller than that observed for bilayers of Al on Cu (30Å) and Al on Ni (60Å) where deposition rates were much higher and samples were much thicker. The reaction species are evident by SEXAFS, where the previous photoemission studies only indicated that changes had occurred. Improved vacuum conditions as compared to the earlier experiments is primarily the reason reactions on deposition were seen in this study as compared to the earlier SEXAFS studies.

Investigation of Thin Pd-Ge Layer Formation Using Synchrotron Vacuum Ultraviolet Photoemission Spectroscopy

1990 ◽  
Vol 181 ◽  
Author(s):  
P. L. Meissner ◽  
J. C. Bravman ◽  
T. Kendelewicz ◽  
K. Miyano ◽  
W. E. Spicer ◽  
...  
Keyword(s):  
Room Temperature ◽  
Vacuum Ultraviolet ◽  
Diffusion Mechanism ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Photoemission Spectroscopy ◽  
Layer Formation ◽  
Primary Reaction ◽  
Ultraviolet Photoemission Spectroscopy

ABSTRACTThe formation of Pd-Ge layers was studied as a function of deposition and annealing using synchrotron Ultraviolet Photoemission Spectroscopy (UPS). Pd depositions ranging in thickness from 0.5 monolayers (ML) to 44 ML were examined in-situ on Ge (111) cleaved in ultra-high vacuum. The primary reaction components appear to be Pd2Ge and PdGe. Comparison of bulk and surface sensitive Ge 3d core levels for even the highest coverages indicates that Ge segregates to the surface at room temperature. Such low temperature segregation suggests that Ge can diffuse via a rapid diffusion mechanism.

IN SITU STM INVESTIGATION OF Ge NANOSTRUCTURES WITH AND WITHOUT Sb ON GRAPHITE

2006 ◽  
Vol 13 (02n03) ◽  
pp. 241-249
Author(s):  
SUNIL SINGH KUSHVAHA ◽  
ZHIJUN YAN ◽  
MAO-JIE XU ◽  
WENDE XIAO ◽  
XUE-SEN WANG
Keyword(s):  
Room Temperature ◽  
Pyrolytic Graphite ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Initial Stage ◽  
Defect Sites ◽  
Substrate Defects

Germanium was deposited onto highly oriented pyrolytic graphite (HOPG) with and without antimony in ultra-high vacuum. The surface morphology was analyzed using in situ scanning tunneling microscopy (STM) at room temperature (RT). The film grows exclusively in 3D island mode and was affected significantly by substrate defects. At initial stage, nucleation of cluster occurred at step edges and defect sites. Later, we found various types of Ge nanostructures on HOPG in different deposition conditions and stages, including cluster chains, cluster islands, nanowires, and double layer ramified islands at RT. Compact Ge islands were observed when depositing at a substrate temperature of 450 K or after an annealing at 600 K following RT deposition. In addition, the pre-deposited Sb on graphite enhances the sticking probability and suppresses the surface diffusion of Ge atoms, resulting in a significant increase in Ge cluster island density on HOPG terraces.

scholarly journals Rare Earth - Fe2 Thin Films Study With Strata™

1996 ◽  
Vol 4 (6) ◽  
pp. 22-23
Author(s):  
J. M. Claude ◽  
J. F. Thiot ◽  
V. Oderno ◽  
C. Dufour
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Room Temperature ◽  
Vacuum Chamber ◽  
High Vacuum ◽  
Growth Direction ◽  
Ultra High Vacuum ◽  
Laves Phases ◽  
20 Nm ◽  
The Rare Earth

The Rare-Earth Laves phases RE-Fe2 (RE represent the Rare-Earth) show large magnetostrictive properties, especially at room temperature. These materials are well characterized when in bulk form, but they have rarely been studied as thin films and one can expect some important effects due to epitaxial growth.A few single crystal layers of RE-Fe2 have been studied (YFe2, TbFe2, DyFe2, ErFe2: and Dy0.7Tb0.3Fe2 known as Terfenol-D). The thickness of these different layers are between 5 and 20 nm and with [110] as a growth direction have been epitaxied. They have been deposited with a Molecular Beam Epitaxy (MBE) in an ultra high vacuum chamber. A [1120] sapphire substrate is recovered by a [110] niobium buffer. The RE and the iron are then co-deposited on the substrate which is maintained at 500°C. Lastly, an Yttrium layer is deposited on the Rare Earth material at a temperature close to ambient.

Untersuchungen zur Epitaxie dünner Goldaufdampfschichten auf Alkalihalogeniden im Ultrahochvakuum

1968 ◽  
Vol 23 (10) ◽  
pp. 1526-1536 ◽  
Author(s):  
R. W. Adam
Keyword(s):  
Substrate Temperature ◽  
Crystal Orientation ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Gold Films ◽  
Oriented Growth ◽  
Deposition Rates ◽  
Deposition Parameters ◽  
Temperature Deposition ◽  
Substrate Temperatures

In the present paper the oriented growth of gold on alkalihalides, cleaved in ultra high vacuum has been investigated. The dependence of the crystal orientation on the deposition parameters substrate temperature, deposition rate, and the physical properties of the substrate were studied systematically. At suitable substrate temperatures and deposition rates it was possible to obtain epitaxial gold films on KCl, KBr and KJ.

Reflection Electron Microscopy (REM) of Surface Steps & Dislocations on GaP(110) & GaAs(110)

1982 ◽  
Vol 40 ◽  
pp. 450-451
Author(s):  
Tung Hsu ◽  
Sumio Iijima
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Heating Stage ◽  
Surface Steps ◽  
Reflection Electron Microscopy ◽  
Electron Microscopes ◽  
High Vacuum Environment

Reflection electron microscopy (REM) in ultra high vacuum environment with heating stage has been reported by Osakabe, et al. In this paper, we present our results in REM imaging of single steps and dislocations using commercial electron microscopes (JEM-100B and Philips-400T) under ordinary pressure (10-7 torr) and room temperature.

Sign in / Sign up

Export Citation Format

Share Document