The Characterization Of Chemical Bath Deposited Cds On Single Crystal InP Substrates

1997 ◽  
Vol 485 ◽  
Author(s):  
G. M. Riker ◽  
M. M. Al-Jassim ◽  
F. S. Hasoon
Keyword(s):  
Electron Microscopy ◽  
Single Crystal ◽  
Surface Cleaning ◽  
Film Morphology ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Fine Grained ◽  
Transmission Electron ◽  
Cds Thin Films ◽  
Inp Substrates

AbstractWe have investigated CdS thin films as possible passivating window layers for InP. The films were deposited on single crystal InP by chemical bath deposition (CBD). The film thickness, as optically determined by ellipsometry, was varied from 500 to 840Å. The film morphology was investigated by high resolution scanning electron microscopy (SEM), whereas the film microstructure was studied by X-ray diffraction (XRD) and cross-sectional transmission electron microscopy (TEM). Most of the films were fine-grained polycrystalline CdS, with some deposition conditions resulting in epitaxial growth. Cross-sectional TEM examination revealed the presence of interface contaminants. The effect of such contaminants on the film morphology and microstructure was studied, and various approaches for InP surface cleaning/treatment were investigated. The epitaxial films were determined to be hexagonal on both the (111) and (100) InP substrates; however, they were heavily faulted.

Effect of Au distribution in NiO/Au film on the ohmic contact formation to p-type GaN

2005 ◽  
Vol 20 (2) ◽  
pp. 456-463 ◽  
Author(s):  
Jiin-Long Yang ◽  
J.S. Chen ◽  
S.J. Chang
Keyword(s):  
Electron Microscopy ◽  
Ohmic Contact ◽  
Incident Angle ◽  
Specific Contact Resistance ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Ohmic Behavior ◽  
Transmission Electron ◽  
Specific Contact ◽  
P Type

The distribution of Au and NiO in NiO/Au ohmic contact on p-type GaN was investigated in this work. Au (5 nm) films were deposited on p-GaN substrates by magnetron sputtering. Some of the Au films were preheated in N2 ambient to agglomerate into semi-connected structure (abbreviated by agg-Au); others were not preheated and remained the continuous (abbreviated by cont-Au). A NiO film (5 nm) was deposited on both types of samples, and all samples were subsequently annealed in N2 ambient at the temperatures ranging from 100 to 500 °C. The surface morphology, phases, and cross-sectional microstructure were investigated by scanning electron microscopy, glancing incident angle x-ray diffraction, and transmission electron microscopy. I-V measurement on the contacts indicates that only the 400 °C annealed NiO/cont-Au/p-GaN sample exhibits ohmic behavior and its specific contact resistance (ρc) is 8.93 × 10−3 Ω cm2. After annealing, Au and NiO contact to GaN individually in the NiO/agg-Au/p-GaN system while the Au and NiO layers become tangled in the NiO/cont-Au/p-GaN system. As a result, the highly tangled NiO-Au structure shall be the key to achieve the ohmic behavior for NiO/cont-Au/p-GaN system.

Determination of Dislocation Densities in Hexagonal Close-Packed Metals using X-Ray Diffraction and Transmission Electron Microscopy

1991 ◽  
Vol 35 (A) ◽  
pp. 593-599 ◽  
Author(s):  
M. Griffiths ◽  
J.E. Winegar ◽  
J.F. Mecke ◽  
R.A. Holt
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Crystal ◽  
Plastic Anisotropy ◽  
Zirconium Alloys ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hexagonal Close Packed ◽  
Transmission Electron ◽  
Dislocation Densities

AbstractX-ray diffraction (XRD) line-broadening analysis has been used to determine dislocation densities in zirconium alloys with hexagonal closepacked (hep) crystal structures and a complex distribution of dislocations reflecting the plastic, anisotropy of the material. The validity of the technique has been assessed by comparison with direct measurements of dislocation densities in deformed polycrystalline and neutron-irradiated single crystal material using transmission electron microscopy (TEM). The results show that-there is good agreement between the XRD and TEM for measurements on the deformed material whereas there is a large discrepancy for measurements on the irradiated single crystal; the XRD measurements significantly underestimating the TEM observations.

Synthesis and Characterization of Plasma Synthesized Nanostructured Magnesia-Yttria Based Nanocomposites

2007 ◽  
Vol 1056 ◽  
Author(s):  
Jafar F. Al-Sharab ◽  
Rajendra Sadangi ◽  
Vijay Shukla ◽  
Bernard Kear
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
Chemical Mapping ◽  
X Ray Diffraction ◽  
Fine Grained ◽  
Transmission Electron ◽  
Spray Method ◽  
Average Grain Size

ABSTRACTPolycrystalline Y2O3 is the material of choice for IR windows since it has excellent optical properties in the visible, and near infra-red band. However, current processing methods yield polycrystalline Y2O3 with large grain size (> 100 μm), which limits the hardness and erosion resistance attainable. One way to improve strength is to develop an ultra-fine grained material with acceptable optical transmission properties. To realize a fine-grained ceramic, one approach is to develop a composite structure, in which one phase inhibits the growth of the other phase during processing. In this study, Y2O3-MgO nanocomposite with various MgO content (20, 50 and 80 mol%) were synthesized using plasma spray method. Extensive characterization techniques including x-ray diffraction, scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Energy Dispersive spectrometry (EDS) were employed to study the synthesized powder as well as the consolidated sample. Transmission Electron Microscopy, as well as EDS chemical mapping, revealed that the consolidated sample have bi-continuous MgO-Y2O3 nanostructure with an average grain size of 200 nm.

Evolution of Epitaxial SixGei1-x Alloys on Si(100) During Thermal Annealing a-Ge/Au Bilayers Deposited on Si Substrate

1992 ◽  
Vol 280 ◽  
Author(s):  
Z. Ma ◽  
L. H. Allen
Keyword(s):  
Single Crystal ◽  
Thermal Annealing ◽  
Rutherford Backscattering Spectrometry ◽  
Solid Phase ◽  
Growth Dynamics ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron

ABSTRACTSolid phase epitaxial (SPE) growth of SixGei1-x alloys on Si (100) was achieved by thermal annealing a-Ge/Au bilayers deposited on single crystal Si substrate in the temperature range of 280°C to 310°C. Growth dynamics was investigated using X-ray diffraction, Rutherford backscattering spectrometry, and cross-sectional transmission electron microscopy. Upon annealing, Ge atoms migrate along the grain boundaries of polycrystalline Au and the epitaxial growth initiates at localized triple points between two Au grains and Si substrate, simultaneously incorporating a small amount of Si dissolved in Au. The Au is gradually displaced into the top Ge layer. Individual single crystal SixGei1-x islands then grow laterally as well as vertically. Finally, the islands coalesce to form a uniform layer of epitaxial SixGe1-x alloy on the Si substrate. The amount of Si incorporated in the final epitaxial film was found to be dependent upon the annealing temperature.

Cross-Sectional TEM Study Of Phase Separation In Reaction Of Ni-Ta Films With GaAs

1985 ◽  
Vol 54 ◽  
Author(s):  
A. Lahav ◽  
M. Eizenberg ◽  
Y. Komem
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Transmission Electron Microscopy ◽  
Phase Separation ◽  
Gaas Substrate ◽  
Auger Spectroscopy ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron

ABSTRACTThe reaction between Ni60Ta40 amorphous alloy and (001) GaAs was studied by cross-sectional transmission electron microscopy, Auger spectroscopy, and x-ray diffraction. At 400°C formation of Ni GaAs at the interface with GaAs was observed. After heat treatment at 600°C in vacuum a layered structure of TaAs/NiGa/GaAs has been formed. The NiGa layer has epitaxial relations to the GaAs substrate. The vertical phase separation can be explained by opposite diffusion directions of nickel and arsenic atoms.

scholarly journals Structural Property Study for GeSn Thin Films

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3645
Author(s):  
Liyao Zhang ◽  
Yuxin Song ◽  
Nils von den Driesch ◽  
Zhenpu Zhang ◽  
Dan Buca ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Threading Dislocations ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron

The structural properties of GeSn thin films with different Sn concentrations and thicknesses grown on Ge (001) by molecular beam epitaxy (MBE) and on Ge-buffered Si (001) wafers by chemical vapor deposition (CVD) were analyzed through high resolution X-ray diffraction and cross-sectional transmission electron microscopy. Two-dimensional reciprocal space maps around the asymmetric (224) reflection were collected by X-ray diffraction for both the whole structures and the GeSn epilayers. The broadenings of the features of the GeSn epilayers with different relaxations in the ω direction, along the ω-2θ direction and parallel to the surface were investigated. The dislocations were identified by transmission electron microscopy. Threading dislocations were found in MBE grown GeSn layers, but not in the CVD grown ones. The point defects and dislocations were two possible reasons for the poor optical properties in the GeSn alloys grown by MBE.

Solid-state reaction of Ru powder in molten AlxBi1−x

1990 ◽  
Vol 5 (4) ◽  
pp. 746-753 ◽  
Author(s):  
R. W. Johnson ◽  
C. M. Garland
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
Alloy System ◽  
Reaction Cross ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Metal Solvent

We describe a low-temperature solid-state interdiffusion technique that allows reaction between spatially separated reacting species and its application in the Al–Ru alloy system. This technique uses a liquid-metal solvent (Bi) as a medium for the transfer of Al to the surface of Ru powder where reaction occurs with the formation of nanocrystalline AlxRu1−x product phases. X-ray diffraction measurements are used to follow the time and temperature dependence of the reaction. Cross-sectional transmission electron microscopy allows direct imaging of the growth and morphology of the AlxRu1−x product phases.

Characterization of ballistically deformed tungsten [100]-, [111]-, and [110]-oriented single crystal penetrators by optical metallography, x-ray diffraction and transmission electron microscopy

2004 ◽  
Vol 19 (12) ◽  
pp. 3451-3462
Author(s):  
R.A. Herring ◽  
W.J. Bruchey ◽  
P.W. Kingman
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Crystal ◽  
Energy Efficient ◽  
Optical Metallography ◽  
Alternative Mechanism ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Wavy Cavity

Single-crystal penetrators of tungsten having orientations of [100], [111], and [110] were ballistically deformed into targets of standard armor material and characterized by optical metallography, x-ray diffraction, and transmission electron microscopy (TEM) methods, which showed significant differences in their deformation mechanisms and microstructures corresponding to their deformation performance as measured by the penetration of the target. The [100] single-crystal penetrator, which produced the most energy efficient deformation, provided a new, alternative mechanism for ballistic deformation by forming small single-crystal blocks, defined by {100} oriented cracks, which rotated during extrusion from the interior to the side of the penetrator while maintaining their single crystal integrity. The [111] single-crystal penetrator transferred mass along allowed, high-angle deformation planes to the penetrator’s side where a buildup of mass mushroomed the tip until the built-up mass let go along the sides of the penetrator, creating a wavy cavity. The [110] penetrator, which produced the least energy-efficient deformation, has only two allowed deformation planes, cracked and rotated to invoke other deformation planes.

scholarly journals Structure refinement of the δ1pphase in the Fe–Zn system by single-crystal X-ray diffraction combined with scanning transmission electron microscopy

2014 ◽  
Vol 70 (2) ◽  
pp. 275-282 ◽  
Author(s):  
Norihiko L. Okamoto ◽  
Katsushi Tanaka ◽  
Akira Yasuhara ◽  
Haruyuki Inui
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Crystal ◽  
Scanning Transmission Electron Microscopy ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission

The structure of the δ1pphase in the iron−zinc system has been refined by single-crystal synchrotron X-ray diffraction combined with scanning transmission electron microscopy. The large hexagonal unit cell of the δ1pphase with the space group ofP63/mmccomprises more or less regular (normal) Zn12icosahedra, disordered Zn12icosahedra, Zn16icosioctahedra and dangling Zn atoms that do not constitute any polyhedra. The unit cell contains 52 Fe and 504 Zn atoms so that the compound is expressed with the chemical formula of Fe13Zn126. All Fe atoms exclusively occupy the centre of normal and disordered icosahedra. Iron-centred normal icosahedra are linked to one another by face- and vertex-sharing forming two types of basal slabs, which are bridged with each other by face-sharing with icosioctahedra, whereas disordered icosahedra with positional disorder at their vertex sites are isolated from other polyhedra. The bonding features in the δ1pphase are discussed in comparison with those in the Γ and ζ phases in the iron−zinc system.

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