Electron Microscopy of Shock Loaded Polycrystalline Beryllium

1974 ◽  
Vol 32 ◽  
pp. 506-507 ◽  
Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens
Keyword(s):  
Electron Microscopy ◽  
Wave Propagation ◽  
Structural Change ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Shock Loading ◽  
Slip Systems ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

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.

Solid-state reaction of Pt thin film with single-crystal (001) β–SiC

1994 ◽  
Vol 9 (3) ◽  
pp. 648-657 ◽  
Author(s):  
J.S. Chen ◽  
E. Kolawa ◽  
M-A. Nicolet ◽  
R.P. Ruiz ◽  
L. Baud ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Single Crystal ◽  
Atomic Scale ◽  
Solid State Reactions ◽  
Main Reaction ◽  
Main Reaction Product ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Interlayer

Thermally induced solid-state reactions between a 70 nm Pt film and a single-crystal (001) β-SiC substrate at temperatures from 300 °C to 1000 °C for various time durations are investigated by 2 MeV He backscattering spectrometry, x-ray diffraction, secondary ion mass spectrometry, scanning electron microscopy, and cross-sectional transmission electron microscopy. Backscattering spectrometry shows that Pt reacts with SiC at 500 °C. The product phase identified by x-ray diffraction is Pt3Si. At 600–900 °C, the main reaction product is Pt2Si, but the depth distribution of the Pt atoms changes with annealing temperature. When the sample is annealed at 1000 °C, the surface morphology deteriorates with the formation of some dendrite-like hillocks; both Pt2Si and PtSi are detected by x-ray diffraction. Samples annealed at 500–900 °C have a double-layer structure with a silicide surface layer and a carbon-silicide mixed layer below in contact with the substrate. The SiC—Pt interaction is resolved at an atomic scale with high-resolution electron microscopy. It is found that the grains of the sputtered Pt film first align themselves preferentially along an orientation of {111}Pt//{001}SiC without reaction between Pt and SiC. A thin amorphous interlayer then forms at 400 °C. At 450 °C, a new crystalline phase nucleates discretely at the Pt-interlayer interface and projects into or across the amorphous interlayer toward the SiC, while the undisturbed amorphous interlayer between the newly formed crystallites maintains its thickness. These nuclei grow extensively down into the substrate region at 500 °C, and the rest of the Pt film is converted to Pt3Si. Comparison between the thermal reaction of SiC-Pt and that of Si–Pt is discussed.

Crystal chemistry of the compound Sr2Bi2CuO6

1990 ◽  
Vol 5 (1) ◽  
pp. 46-52 ◽  
Author(s):  
R. S. Roth ◽  
C. J. Rawn ◽  
L. A. Bendersky
Keyword(s):  
Electron Diffraction ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Crystal Chemistry ◽  
Superconducting Phase ◽  
X Ray Diffraction ◽  
Monoclinic Symmetry ◽  
X Ray ◽  
Symmetry Space ◽  
Symmetry Space Group

The compound Sr2Bi2CuO6 should nominally be the phase with n = 1 of the high Tc superconducting series Sr2Bi2CanO4+2n. However, the superconducting phase with n = 1 (with no CaO) occurs only with a gross deficiency in SrO content. Instead, at the composition Sr2Bi2CuO6, a different phase is formed with an x-ray diffraction pattern considerably different from that expected for the n −1 member of the series. This phase has been found, by a combination of electron diffraction and single crystal and powder x-ray diffraction, to have a commensurate lattice with monoclinic symmetry, space group C2/m or Cm, a = 24.473 (2), b = 5.4223 (5), c = 21.959 (2)A, and β = 105.40 (1)°. The actual composition of this phase may be deficient in CuO by as much as 1.0 mole %.

scholarly journals SYSU-6, A New 2-D Aluminophosphate Zeolite Layer Precursor

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2972 ◽  
Author(s):  
Jiang-Zhen Qiu ◽  
Long-Fei Wang ◽  
Jiuxing Jiang
Keyword(s):  
Electron Microscopy ◽  
Single Crystal ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
X Ray Diffraction ◽  
Structure Directing Agent ◽  
X Ray ◽  
Uv Raman ◽  
Angle Spinning ◽  
Inorganic Framework

Two-dimensional aluminophosphate is an important precursor of phosphate-based zeolites; a new Sun Yat-sen University No. 6 (SYSU-6) with |Hada|2[Al2(HPO4)(PO4)2] has been synthesized in the hydrothermal synthesis with organic structure-directing agent (OSDA) of N,N,3,5-tetramethyladamantan-1-amine. In this paper, SYSU-6 is characterized by single-crystal/powder X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray analysis, transmission electron microscopy, infrared and UV Raman spectroscopy, solid-state 27Al, 31P and 13C magic angle spinning (MAS) NMR spectra, and elemental analysis. The single-crystal X-ray diffraction structure indicates that SYSU-6 crystallized in the space group P21/n, with a = 8.4119(3), b = 36.9876(12), c = 12.5674(3), α = 90°, β = 108.6770(10)°, γ = 90°, V = 3704.3(2) Å3, Z = 4, R = 5.12%, for 8515 observed data (I > 2σ(I)). The structure has a new 4,12-ring layer framework topology linked by alternating AlO4 and PO4 tetrahedra. The organic molecules reside between the layers and are hydrogen-bonded to the inorganic framework. The new type of layer provides a greater opportunity to construct zeolite with novel topology.

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.

Room temperature recrystallization of nanocrystalline thin copper foils

1994 ◽  
Vol 362 ◽  
Author(s):  
J. Dille ◽  
J.-L. Delplancke ◽  
J. Charlier ◽  
R. Winand
Keyword(s):  
Electron Microscopy ◽  
Diffraction Pattern ◽  
Room Temperature ◽  
Structural Evolution ◽  
Preferential Orientation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Copper Foils ◽  
Different Temperatures ◽  
Anodized Titanium

AbstractThin copper foils (100 micrometers thick) are produced by electrolysis on anodized titanium substrates. A sharp distribution of grain diameter is observed around 200 nanometers. The X-ray diffraction pattern shows a slight preferential orientation of the crystals with the (111) planes parallel to the substrate. This X-ray diffraction pattern evolves at room temperature. After 60 days, a preferential orientation of the (200) planes parallel to the substrate is observed. This effect is associated with the recrystallisation of the foil with growth of large copper grains (diameter higher than 5 micrometers) as observed by high resolution transmission electron microscopy.The structural evolution of the copper foils is studied by electron microscopy, X-ray and electron diffractions at different temperatures.The mechanical properties of the foils are also studied as a function of time after electrodeposition.

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.

Metal Bonding in SiC Based Substrates

2005 ◽  
Vol 483-485 ◽  
pp. 781-784 ◽  
Author(s):  
Igor Matko ◽  
Bernard Chenevier ◽  
Roland Madar ◽  
H. Roussel ◽  
Stephane Coindeau ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Crystal ◽  
Structure Evolution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Bonding ◽  
Silicide Layer ◽  
Transmission Electron ◽  
Single Crystal Sic

QuaSiC TM substrates can be obtained by transferring a single crystal SiC layer onto a poly SiC substrate using the Smart Cut TM technology. The structure evolution of metal bonding (W-Si silicide) layer has been investigated by Transmission Electron Microscopy and X-ray diffraction. Results indicate that the metal bonding film is made of W5Si3. The film is discontinuous and strained. Annealing releases stress at least partially.

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