HRTEM investigation of intralayer and interlayer stacking defects and pyrophyllite interlayers in illite

2010 ◽  
Vol 74 (3) ◽  
pp. 451-461 ◽  
Author(s):  
Tao Chen ◽  
Hejing Wang ◽  
Roger Mason ◽  
Li Chen
Keyword(s):  
Electron Microscope ◽  
Early Stage ◽  
Energy Dispersive Spectrometer ◽  
Tetrahedral Sheet ◽  
Al Content ◽  
Transmission Electron ◽  
Metastable Structures ◽  
Interlayer Region ◽  
Complex Structural ◽  
High Al Content

AbstractMetastable authigenic 1M illite from shale of diagenetic grade has been studied using a high-resolution transmission electron microscope (HRTEM) equipped with energy-dispersive spectrometer, X-ray diffraction, and scanning electron microscope. The illite occurs as deformed flakes deficient in interlayer K+ cations with 0.6 per half cell, and with abnormally high Al in both octahedral and tetrahedral sites. Complex structural adjustments reflecting the unusual chemical composition are observed in images of illite at near-atomic resolution. Different distances and directions of intralayer shift between the upper tetrahedral sheet and the lower tetrahedral sheet within 2:1 layers are found in this sample. Intralayer undershift structure coupled with interlayer displacement is found in a 1M illite crystal, and intralayer overshift structure coupled with no interlayer displacement is found in a 1M domain of a larger crystal. Two tetrahedral sheets across the interlayer region sometimes deviate from ideal positions causing interlayer displacement. Two pyrophyllite layers are found overlying a stack of ordered 1M illite layers, and are overlain by illite layers with anomalous interlayer offsets. This offset is considered to result from an increase in the lateral dimensions of the tetrahedral sheet due to anomalous high Al content. Our observation of intralayer and interlayer deficiencies indicate that authigenic illite that crystallized in the early stage of diagenesis at low temperatures tends to give rise to heterogeneous, disordered, and metastable structures.

Characterization of submicrometer fluid Inclusions in minerals by Analytical/Transmission Electron Microscopy and electron diffraction

1990 ◽  
Vol 48 (4) ◽  
pp. 424-424
Author(s):  
George Guthrie ◽  
David Veblen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Light Microscopy ◽  
Fluid Inclusions ◽  
Energy Dispersive Spectrometer ◽  
Analytical Transmission Electron Microscopy ◽  
Transmission Electron

The nature of a geologic fluid can often be inferred from fluid-filled cavities (generally <100 μm in size) that are trapped during the growth of a mineral. A variety of techniques enables the fluids and daughter crystals (any solid precipitated from the trapped fluid) to be identified from cavities greater than a few micrometers. Many minerals, however, contain fluid inclusions smaller than a micrometer. Though inclusions this small are difficult or impossible to study by conventional techniques, they are ideally suited for study by analytical/ transmission electron microscopy (A/TEM) and electron diffraction. We have used this technique to study fluid inclusions and daughter crystals in diamond and feldspar.Inclusion-rich samples of diamond and feldspar were ion-thinned to electron transparency and examined with a Philips 420T electron microscope (120 keV) equipped with an EDAX beryllium-windowed energy dispersive spectrometer. Thin edges of the sample were perforated in areas that appeared in light microscopy to be populated densely with inclusions. In a few cases, the perforations were bound polygonal sides to which crystals (structurally and compositionally different from the host mineral) were attached (Figure 1).

Microstructure and Distribution of Low Content Elements in AlNiCo 9

2017 ◽  
Vol 898 ◽  
pp. 1669-1674 ◽  
Author(s):  
Bin Shao ◽  
Bing Bing Li ◽  
Chun Hong Li ◽  
Yi Long Ma ◽  
Qiang Zheng ◽  
...  
Keyword(s):  
Magnetic Force ◽  
Magnetic Domain ◽  
Magnetic Force Microscope ◽  
X Ray Diffraction ◽  
Rich Phase ◽  
X Ray ◽  
Al Content ◽  
Transmission Electron ◽  
Titanium Sulfide ◽  
High Al Content

The microstructure and the chemistry distribution of AlNiCo 9 samples were characterized by the X-ray diffraction, magnetic force microscope, field emission scanning electron microscopy and transmission electron microscope. An interface of a high Al content was formed near the FeCo-rich phases with a size of about 30 nm. S elements mainly combined with Ti to form titanium sulfide bars with the length between 70-150 μm, while S elements was not confirmed in the nanostructured FeCo-rich phase and AlNi-rich phase. Si and Nb preferably existed in the NiAl-rich phase, and a higher content Nb near the Cu precipitate boundary was observed. Moreover, the magnetic domain structure of AlNiCo 9 was also studied.

HRTEM Observation of the Age Hardening Precipitates in Mg-Zn Alloy

2007 ◽  
Vol 26-28 ◽  
pp. 157-160
Author(s):  
Shogo Mori ◽  
Tokimasa Kawabata ◽  
Kenji Matsuda ◽  
Susumu Ikeno
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Early Stage ◽  
Age Hardening ◽  
Aged Specimen ◽  
Transmission Electron ◽  
Hrtem Observation ◽  
Peak Aged ◽  
Zn Alloy ◽  
Different Parts

The age hardening precipitates of Mg-4.7mass%Zn alloy aged at 423K,473K were studied by using high-resolution transmission electron microscope (HRTEM). Contrasts of mono layers were confirmed to exist on the (0001) and (1100) matrix planes. It was considered that the contrast of mono layer was plate-like shape, and identified as pre-precipitates from as-quenched stage to early stage of aging at 473K for 32h . In the peak aged specimen of aged at 473K, the β1’ phase was observed. The β1’ phase has a rod-like shape and parallel to c-axis of Mg matrix. It can be observed orientation relationship between Mg matrix and β1’phase has not only same parts to previous reports but also different parts in one β1’ phase .

SURFACE MODIFICATIONS WITH LASER SYNTHESIZED Mo MODIFIED COATING

2013 ◽  
Vol 20 (01) ◽  
pp. 1350003 ◽  
Author(s):  
LU SUN ◽  
HAO CHEN ◽  
BO LIU
Keyword(s):  
Electron Microscope ◽  
Composite Coating ◽  
Laser Cladding ◽  
Energy Dispersive Spectrometer ◽  
Surface Modifications ◽  
Fine Grain ◽  
Transmission Electron ◽  
Ta15 Titanium Alloy ◽  
Surface Performance ◽  
Ta15 Alloy

Mg–Cu–Al was first used to improve the surface performance of TA15 titanium alloys by means of laser cladding technique. The synthesis of hard composite coating on TA15 titanium alloy by laser cladding of Mg–Cu–Al–B4C/Mo pre-placed powders was investigated by means of scanning electron microscope, energy dispersive spectrometer and high resolution transmission electron microscope. Experimental results indicated that such composite coating mainly consisted of TiB2 , TiB , TiC , Ti3Al and AlCuMg . Compared with TA15 alloy substrate, an improvement of wear resistance was observed for this composite coating due to the actions of fine grain, amorphous and hard phase strengthening.

Damage and Lattice Strain in Ion-Irradiated AlxGai-xAs

1994 ◽  
Vol 354 ◽  
Author(s):  
P. Partyka ◽  
R.S. Averback ◽  
D.V. Forbes ◽  
J.J. Coleman ◽  
P. Ehrhart ◽  
...  
Keyword(s):  
Rutherford Backscattering Spectrometry ◽  
Lattice Parameter ◽  
Large Strains ◽  
X Ray Diffraction ◽  
Al Content ◽  
Plane Lattice ◽  
Transmission Electron ◽  
Out Of Plane ◽  
Radiation Induced ◽  
High Al Content

AbstractRadiation-induced damage and strain in AlxGai-xAs (x=5 to 1) were investigated by measurements of the lattice parameter using x-ray diffraction. Irradiations employed MeV C, Ar and Au ion beams with a substrate temperature of 80 K. For samples with high Al content, the out-of-plane lattice parameter increased with fluence at low doses, saturated, and then decreased to nearly its original value. The in-plane lattice parameter did not change, throughout. These results were independent of the irradiation particle when scaled by damage energy. For the Al.5Ga.5As samples, however, the out-of-plane lattice parameter increased monotonically with dose to large strains until the layer amorpnized. Selected samples were examined by high resolution and conventional transmission electron microscopy (TEM). Channeling Rutherford backscattering spectrometry (CRBS) was also employed to monitor the buildup of damage in many samples. Recovery of the lattice parameter during subsequent thermal annealing was also investigated.

Microstructural Evolution of Ba2Ycu3O7 Superconductor by Electron Irradiation in a Transmission Electron Microscope

1989 ◽  
Vol 169 ◽  
Author(s):  
Kensuke ShiraiShi ◽  
Hiroshi Itoh
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Electron Irradiation ◽  
Early Stage ◽  
Lattice Image ◽  
Density Region ◽  
Transmission Electron ◽  
High Density Region ◽  
Intense Electron Beam ◽  
Intense Electron

AbstractMicrostructural changes in a Ba2YCu3O7 pellet were continuously observed during electron irradiation in a transmission electron microscope operating at 200 kV. Twin lamellae of 2~10 nm in thickness with 1~50 nm spacings were seen parallel to the lattice image of (001) plane with 1.17 nm in lattice spacing. The tip of the twin was lenticular and the (001) lattice fringes were distorted around the tip. Upon intense electron beam illumination, the lamellae faded at the tip and the thickness gradually decreased which increased the spacing in the high density region. Defect clusters of about 10 nm in size were produced in the very early stage of electron illumination.

Research on Microstructure Evolution of Spray Forming FVS0812 Alloy Varies with Temperature

2014 ◽  
Vol 543-547 ◽  
pp. 3729-3732
Author(s):  
Rong Hua Zhang ◽  
Biao Wu ◽  
Xiao Ping Zheng
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Energy Dispersive Spectrometer ◽  
Temperature Stability ◽  
Optical Microscope ◽  
Spray Forming ◽  
Effect Of Temperature ◽  
High Temperature Stability ◽  
Transmission Electron ◽  
Microstructure Of The Material

Heat-resistant FVS0812 alloys were prepared by spray forming technique. The effect of temperature on microstructure the alloys was studied by optical microscope (OM), transmission electron microscope (TEM) with energy dispersive spectrometer (EDS), differential scanning calorimeter (DSC) in this paper. The research results show that the microstructure of the material doesnt change obviously after being hold for 3 hours at 420°C temperature. When the temperature is over 420°C, the second coarse phases are found in the alloy. The studies on the microstructure of the alloy exposed at 400°C for 100 hours show that the alloy has excellent high temperature stability.

The Investigation of Microstructure of Pt/Ti Explosive Clad Interface

2005 ◽  
Vol 475-479 ◽  
pp. 3855-3858 ◽  
Author(s):  
Shi Zhong Wei ◽  
Yan Li ◽  
Jin Hua Zhu
Keyword(s):  
Electron Microscope ◽  
Crystal Size ◽  
Energy Dispersive Spectrometer ◽  
Martensite Phase ◽  
Crystal Layer ◽  
Orthorhombic Crystal System ◽  
Orthorhombic Crystal ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Microstructure in anchoring site of Pt/Ti explosive clad Plate was observed, tested and analyzed by analytical and high resolution transmission electron microscope, X-ray diffractometer, scanning electron microscope and energy-dispersive spectrometer. An intermittent micro-crystal layer was observed in anchoring area, with thickness of 2 um. The inner crystal size was from some nanometer. to hundreds of nanometer. Some crystal had defects in it, such as staggered layer. The layer was composed of metal compound, like PtTi，Pt5Ti3，Pt3Ti，Ti3Pt and etc. The direct Pt—Ti anchoring area, hexagonal Ti variation-orthorhombic crystal system, α″-Ti metastable martensite phase and bicrystals with partial deformation were also observed. The research of microstructure in anchoring area revealed the nature of explosive compound in metallurgical anchoring.

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