The Experts below are selected from a list of 51 Experts worldwide ranked by ideXlab platform
Li Y - One of the best experts on this subject based on the ideXlab platform.
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An electrostatic Si e-gun and a high temperature elemental B source for Si heteroepitaxial growth
1996Co-Authors: Scarinci F, Casella A, Lagomarsino S, Fiordelisi M, Strappaveccia P, Gambacorti N, Mg Grimaldi, Li YAbstract:In this paper we present two kind of sources used in Si MBE growth: a Si source where an electron beam is electrostatically deflected onto a Si rod and a high temperature B source to be used for p-doping. Both sources have been designed and constructed at IESS. The Si source is constituted of a Si rod mounted on a 3/4 '' flange with high-voltage connector. A W filament held at high voltage (up to 2000 V) is heated by direct current. Electrons from the filament are electrostatically focused onto the Si rod which is grounded, This mounting allows a minimum heating dispersion and no contamination, because the only hot objects are the Si rod and the W filament which is mounted in such a way that it cannot see the substrate, Growth rates of 10 Angstrom/min on a substrate at 20 cm from the source have been measured. Auger and LEED have shown no contamination. The B source is constituted of a Graphite block heated by direct current. A pyrolitic Graphite crucible put in the Graphite Heater contains the elemental B, The cell is water cooled and contains Ta screens to avoid heat dispersion, It has been tested up to a temperature of 1700 degrees C. P-doped Si1-xCex layers have been grown and B concentration has been measured by SIMS, A good central and reproducibility has been attained.Chemistry, PhysicalMaterials Science, Coatings & FilmsPhysics, AppliedPhysics, Condensed MatterSCI(E)
G. Travish - One of the best experts on this subject based on the ideXlab platform.
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Creation of plasma density transitions short compared to the plasma skin depth
2015Co-Authors: M. C. Thompso, J. . Rosenzweig, G. TravishAbstract:A plasma based electron beam source apparatus is described which creates a plasma with two distinct density regions separated by a transition which is shorter than the plasma skin depth k−1p of either region. This sharp density modulation is achieved by using a perforated stainless steel screen to filter half of a diffusing plasma column. A simple physical model predicts that the length of the plasma density transition will vary with the distance from the screen. For a weakly magnetized plasma, the transition length will be twice the distance, on a line normal to the screen plane, from the screen edge to the location where the transition is measured. The plasma column is generated using an argon discharge plasma source. It has a peak density of approximately 3.5 x 1013 cm−3 and a FWHM width of 5 cm. The discharge source utilizes a 7.5 cm diameter LaB6 disc cathode heated to 1300 ◦ C using a Graphite Heater. The plasma column is filtered with a 78 µm thick stainless steel sheet with 152 µm holes and 21 % open area. Plasma density transitions with lengths between 0.74k−1p and 0.95k −1 p were measured
Lee, Kanani K. M - One of the best experts on this subject based on the ideXlab platform.
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Efficient Graphite ring Heater suitable for diamond-anvil cells to 1300 K
'AIP Publishing', 2013Co-Authors: Du Zhixue, Miyagi Lowell, Amulele George, Lee, Kanani K. MAbstract:In order to generate homogeneous high temperatures at high pressures, a ring-shaped Graphite Heater has been developed to resistively heat diamond-anvil cell (DAC) samples up to 1300 K. By putting the Heater in direct contact with the diamond anvils, this Graphite Heater design features the following advantages: (1) efficient heating: sample can be heated to 1300 K while the DAC body temperature remains less than 800 K, eliminating the requirement of a special alloy for the DAC; (2) compact design: the sample can be analyzed with in situ measurements, e.g., x-ray, optical, and electrical probes are possible. In particular, the side access of the Heater allows for radial x-ray diffraction (XRD) measurements in addition to traditional axial XRD.5 page(s
Scarinci F - One of the best experts on this subject based on the ideXlab platform.
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An electrostatic Si e-gun and a high temperature elemental B source for Si heteroepitaxial growth
1996Co-Authors: Scarinci F, Casella A, Lagomarsino S, Fiordelisi M, Strappaveccia P, Gambacorti N, Mg Grimaldi, Li YAbstract:In this paper we present two kind of sources used in Si MBE growth: a Si source where an electron beam is electrostatically deflected onto a Si rod and a high temperature B source to be used for p-doping. Both sources have been designed and constructed at IESS. The Si source is constituted of a Si rod mounted on a 3/4 '' flange with high-voltage connector. A W filament held at high voltage (up to 2000 V) is heated by direct current. Electrons from the filament are electrostatically focused onto the Si rod which is grounded, This mounting allows a minimum heating dispersion and no contamination, because the only hot objects are the Si rod and the W filament which is mounted in such a way that it cannot see the substrate, Growth rates of 10 Angstrom/min on a substrate at 20 cm from the source have been measured. Auger and LEED have shown no contamination. The B source is constituted of a Graphite block heated by direct current. A pyrolitic Graphite crucible put in the Graphite Heater contains the elemental B, The cell is water cooled and contains Ta screens to avoid heat dispersion, It has been tested up to a temperature of 1700 degrees C. P-doped Si1-xCex layers have been grown and B concentration has been measured by SIMS, A good central and reproducibility has been attained.Chemistry, PhysicalMaterials Science, Coatings & FilmsPhysics, AppliedPhysics, Condensed MatterSCI(E)
Iva Uzunov - One of the best experts on this subject based on the ideXlab platform.
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Nanosized Silicon Carbide Obtained from Rice Husks
2016Co-Authors: Dimita Radev, Iva UzunovAbstract:Abstract. Two ways to obtain nanosized silicon carbide (SiC) powders from the products of thermal decomposition of rice hulls and posterior thermal and chemical treatment of SiO2-C precursors are shown in the present paper. The reagents and products were analyzed using BET, DTA, IR, XRD and SEM/TEM. Precursors obtained from rice husks containing pure SiO2 and a controlled SiO2-C ratio were used for the synthesis of SiC. The synthesis of SiC proceeded for 30-45 min in a Graphite Heater furnace under protective Ar atmosphere at relatively low temperatures (1450oC-1550oC). Nanosized dimensions of reagents obtained from rice husks and their high activity allow obtaining SiC in relatively milder thermal regimes. TEM and XRD analysis revealed synthesis of nanostructured mainly β-SiC with a mean crystallite size of 40-100 nm. Due to their purity and nano-scale properties, the products obtained are appropriate for production of bulk SiC or design of SiC–based ultra high-temperature materials using the methods of powder metallurgy
