Growth of au on a ge (111) surface

1992 ◽  
Vol 50 (2) ◽  
pp. 1434-1435
Author(s):  
D.N. Dunn ◽  
P. Xu ◽  
L.D. Marks
Keyword(s):  
Growth Mechanism ◽  
Noble Metals ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Two Dimensional ◽  
Temperature Growth ◽  
Wide Range ◽  
Device Applications

The growth of noble metals such as Au and Ag on Si and Ge is of considerable interest for modern semi-conductor device applications. Several groups have investigated the room temperature growth of Au films on Ge (111) substrates using RHEED, LEED, UPS, as well as other techniques. It is clear from these investigations that the growth of Au on Ge (111) proceeds by a mechanism contrary to what might be expected by comparison to the growth of Au on Si (111). In general most of these studies have looked in two regimes, the first being simple room temperature growth over a wide range of Au coverages from a few tenths of a monolayer up to 100 Å in thickness. The second regime is the behavior of these Au films as a function of annealing temperature. Using RHEED and LEED to study a wide range of Au coverages, Le Lay and coworkers have found that the growth mechanism of Au films proceeds by the appearance of two dimensional close packed domains which do not completely cover the surface.

Chloride promoted room temperature preparation of silver nanoparticles on two dimensional tungsten oxide nanoarchitectures for the catalytic oxidation of tertiary N-compounds to N-oxides

Nanoscale ◽  
2015 ◽  
Vol 7 (37) ◽  
pp. 15197-15208 ◽  
Author(s):  
Shilpi Ghosh ◽  
Shankha S. Acharyya ◽  
Malika Kumar ◽  
Rajaram Bal
Keyword(s):  
Silver Nanoparticles ◽  
Tungsten Oxide ◽  
Room Temperature ◽  
Catalytic Performance ◽  
Two Dimensional ◽  
Facile Synthesis ◽  
Wide Range ◽  
Synthesis Protocol ◽  
N Compounds ◽  
Temperature Preparation

A halide ion promoted 2D silver tungsten-based nanoarchitecture, synthesized by a facile synthesis protocol, exhibited high catalytic performance for the production of a wide range of N-oxides.

Room-temperature wide-range photoluminescence and semiconducting characteristics of two-dimensional pure metallic Zn nanoplates

RSC Advances ◽  
2012 ◽  
Vol 2 (5) ◽  
pp. 2123 ◽  
Author(s):  
Jin-Han Lin ◽  
Yong-Jie Huang ◽  
Yan-Ping Su ◽  
Che-An Liu ◽  
Rupesh S. Devan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Two Dimensional ◽  
Wide Range

Room-temperature growth of two-dimensional gold films on GaAs(001)

1987 ◽  
Vol 36 (11) ◽  
pp. 6231-6234 ◽  
Author(s):  
T. G. Andersson ◽  
G. Le Lay ◽  
J. Kanski ◽  
S. P. Svensson
Keyword(s):  
Room Temperature ◽  
Gold Films ◽  
Two Dimensional ◽  
Temperature Growth

Low-Density InAs Quantum Dots Growth by Molecular Beam Epitaxy

2012 ◽  
Vol 442 ◽  
pp. 12-15
Author(s):  
Zhan Guo Li ◽  
Ming Hui You ◽  
Guo Jun Liu ◽  
Xin Gao ◽  
Lin Li ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Molecular Beam Epitaxy ◽  
Room Temperature ◽  
Molecular Beam ◽  
Annealing Temperature ◽  
Layer Growth ◽  
Low Density ◽  
Inas Quantum Dots ◽  
Temperature Growth ◽  
Spacer Layer

We investigate the growth of low-density(~4×108cm-2) InAs quantum dots (QDs) on GaAs by molecular beam epitaxy,with emission wavelength up to 1.3 µm at room temperature were achieved. The QDs density are sensitive to growth temperature,growth rate.The optical properties of the QDs annealing temperature used after spacer layer growth that is attributed to the suppressed In segregation from the QDs into the cap layer, reduced the strain in the QDs,significant decrease of integrated PL intensity was observed as the annealing temperature increases.

scholarly journals The Fabrication of the Infrared CdSe Doped With Cu Photodetector

2016 ◽  
Vol 8 (3) ◽  
pp. 96
Author(s):  
Hassan H. Mohammed ◽  
Salwan K. J. AL-Ani
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
Visible Region ◽  
Film Structure ◽  
Electromagnetic Spectrum ◽  
Wide Range ◽  
Implementation Method ◽  
First Time

In this work, the implementation method of the CdSe doped with Cu (CdSe: Cu) photodetector is presented. This detector is prepared by vacuum evaporation of CdSe films on glass substrate followed by vacuum annealing under an argon atmosphere for doping with copper. This detector is found, for the first time, to cover a wide range of the infrared besides the visible region of the electromagnetic spectrum. This finding of the wavelength tuning is due to the localized energy states of copper atoms inside the band gap of the CdSe. This tuning is compared with recent work in the corresponding colloidal CdSe-ZnS core shell quantum dots and with the quantum well (QWIR) and quantum dots (QDIR) infrared detectors. The major significance of this developed detector is in its synthesis simplicity and its fabrication processes costs in comparison with that of the (QWIR) and (QDIR) detectors. The structural analysis results demonstrated that the vacuum annealing in competition with the doping concentration improves significantly the film structure. Better crystalline structure was reported at 5 wt% of Cu concentration and at annealing temperature of 350 ºC. Besides the measured detectivity at room temperature is D*=2.31×108 cm Hz1/2W-1. This value approaches the detectivity of the state of art mercury cadmium telluride (MCT). This result paves the way for further investigations and improvements.

scholarly journals Low-Temperature Growth of Shewanella oneidensis MR-1

2005 ◽  
Vol 71 (2) ◽  
pp. 811-816 ◽  
Author(s):  
Randa Abboud ◽  
Radu Popa ◽  
Virginia Souza-Egipsy ◽  
Carol S. Giometti ◽  
Sandra Tollaksen ◽  
...  
Keyword(s):  
Room Temperature ◽  
Doubling Time ◽  
Shewanella Oneidensis ◽  
Maximum Growth ◽  
Lag Phase ◽  
Temperature Growth ◽  
Wide Range ◽  
Mesophilic Bacterium ◽  
Cellular Lipids ◽  
Higher Temperature

ABSTRACT Shewanella oneidensis MR-1 is a mesophilic bacterium with a maximum growth temperature of ≈35°C but the ability to grow over a wide range of temperatures, including temperatures near zero. At room temperature (≈22°C) MR-1 grows with a doubling time of about 40 min, but when moved from 22°C to 3°C, MR-1 cells display a very long lag phase of more than 100 h followed by very slow growth, with a doubling time of ≈67 h. In comparison to cells grown at 22°C, the cold-grown cells formed long, motile filaments, showed many spheroplast-like structures, produced an array of proteins not seen at higher temperature, and synthesized a different pattern of cellular lipids. Frequent pilus-like structures were observed during the transition from 3 to 22°C.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

Growth of near noble metal Pd and Pt thin film silicides morphology and structure

1984 ◽  
Vol 42 ◽  
pp. 498-499
Author(s):  
E. I. Alessandrini ◽  
M. O. Aboelfotoh
Keyword(s):  
Noble Metals ◽  
Annealing Temperature ◽  
Chemical Compounds ◽  
Barrier Properties ◽  
Solid State Reactions ◽  
Transmission Electron ◽  
Stable Chemical ◽  
Metal Thickness ◽  
Amorphous Si ◽  
Si Films

Considerable interest has been generated in solid state reactions between thin films of near noble metals and silicon. These metals deposited on Si form numerous stable chemical compounds at low temperatures and have found applications as Schottky barrier contacts to silicon in VLSI devices. Since the very first phase that nucleates in contact with Si determines the barrier properties, the purpose of our study was to investigate the silicide formation of the near noble metals, Pd and Pt, at very thin thickness of the metal films on amorphous silicon.Films of Pd and Pt in the thickness range of 0.5nm to 20nm were made by room temperature evaporation on 40nm thick amorphous Si films, which were first deposited on 30nm thick amorphous Si3N4 membranes in a window configuration. The deposition rate was 0.1 to 0.5nm/sec and the pressure during deposition was 3 x 10 -7 Torr. The samples were annealed at temperatures in the range from 200° to 650°C in a furnace with helium purified by hot (950°C) Ti particles. Transmission electron microscopy and diffraction techniques were used to evaluate changes in structure and morphology of the phases formed as a function of metal thickness and annealing temperature.

Evaluation of 99mTc-Label led Vitamin K4 as an Agent for Testicular Imaging

1991 ◽  
Vol 30 (01) ◽  
pp. 35-39 ◽  
Author(s):  
H. S. Durak ◽  
M. Kitapgi ◽  
B. E. Caner ◽  
R. Senekowitsch ◽  
M. T. Ercan
Keyword(s):  
Soft Tissue ◽  
Room Temperature ◽  
Normal Subjects ◽  
Left Testis ◽  
Wide Range ◽  
Activity Ratios ◽  
The Right ◽  
Radioactivity Levels

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.

Aromatic Volatile Composition of Celery and Celeriac Cultivars

HortScience ◽  
1990 ◽  
Vol 25 (5) ◽  
pp. 556-559 ◽  
Author(s):  
Fredy Van Wassenhove ◽  
Patrick Dirinck ◽  
Georges Vulsteke ◽  
Niceas Schamp
Keyword(s):  
Volatile Compounds ◽  
Chromatographic Method ◽  
Apium Graveolens ◽  
Volatile Components ◽  
Two Dimensional ◽  
Qualitative Composition ◽  
Volatile Composition ◽  
Wide Range ◽  
Gas Chromatographic Method ◽  
Identification And Quantification

A two-dimensional capillary gas chromatographic method was developed to separate and quantify aromatic volatiles of celery in one analysis. The isolation, identification, and quantification of the volatile compounds of four cultivars of blanching celery (Apium graveolens L. var. dulce) and six cultivars of celeriac (Apium graveolens L. var. rapaceum) are described. The qualitative composition of Likens-Nickerson extracts of both cultivars is similar. The concentration of terpenes and phthalides, the key volatile components, found in various cultivars of both celery and celeriac varied over a wide range.

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