HRTEM Observation of Rod-Shape Precipitates in Al-Mg-Si-Ag Alloy Aged at 523 K

2007 ◽  
Vol 561-565 ◽  
pp. 243-246 ◽  
Author(s):  
Junya Nakamura ◽  
Kenji Matsuda ◽  
Yoshio Nakamura ◽  
Tatsuo Sato ◽  
Susumu Ikeno
Keyword(s):  
Crystal Structure ◽  
Electron Microscope ◽  
High Resolution ◽  
Electron Diffraction ◽  
Metastable Phase ◽  
X Ray ◽  
Β Phase ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Hrtem Observation

The purpose of this study is to identify the crystal structure of metastable phase in Ag added Al-Mg-Si alloy to compare the formation of β’-phases in Al-Mg-Si alloys without Ag, using images of high resolution transmission electron microscope (HRTEM), selected area electron diffraction (SAED) patterns and an energy dispersive X-ray spectroscopy (EDS). The result of SAED patterns and HRTEM images have been simulated and compared with images then SAED patterns obtained from actual precipitates. SAED patterns and HRTEM images obtained from metastable phase in the Ag added Al-Mg-Si alloy showed similar to those of β’-phase in Al-Mg-Si alloy without Ag and the lattice spacings changed because of the effect of Ag.

The Effect of Ag-Addition on Crystal Structure of β'-Phase in Al-Mg-Si Alloy

2006 ◽  
Vol 519-521 ◽  
pp. 511-514 ◽  
Author(s):  
Junya Nakamura ◽  
Kenji Matsuda ◽  
Yoshio Nakamura ◽  
Tatsuo Sato ◽  
Susumu Ikeno
Keyword(s):  
Crystal Structure ◽  
Electron Microscope ◽  
High Resolution ◽  
Metastable Phase ◽  
Ag Addition ◽  
X Ray ◽  
Β Phase ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Diffraction Patterns

The purpose of this study is identity the crystal structure of metastable phase in Ag added Al-Mg-Si alloy by comparing the β’-phases in Al-Mg-Si alloy without Ag, using images of high resolution transmission electron microscope (HRTEM), selected area electron diffraction patterns (SADPs) and an energy dispersive X-ray spectroscopy (EDS). The result of SADPs and HRTEM images have been simulated and compared with images and SADPs obtained from actual precipitates. SADPs and HRTEM images obtained from metastable phase in the Ag added Al-Mg-Si alloy showed similar to those of β’-phase in Al-Mg-Si alloy without Ag and had different lattice spacings because of the effect of Ag.

Crystal Structure of the β'-Phase in Al-Mg-Si-Ag Alloy

2007 ◽  
Vol 539-543 ◽  
pp. 837-841 ◽  
Author(s):  
Kenji Matsuda ◽  
Junya Nakamura ◽  
Yoshio Nakamura ◽  
Tatsuo Sato ◽  
Susumu Ikeno
Keyword(s):  
Crystal Structure ◽  
Electron Microscope ◽  
High Resolution ◽  
Metastable Phase ◽  
Careful Analysis ◽  
X Ray ◽  
Β Phase ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Diffraction Patterns

The crystal structure of metastable phase in Ag added Al-Mg-Si alloy was investigated by comparing the β’-phases in Al-Mg-Si alloy without Ag, using images of high resolution transmission electron microscope (HRTEM), selected area electron diffraction patterns (SADPs) and an energy dispersive X-ray spectroscopy (EDS). SADPs and HRTEM images obtained from metastable phase in the Ag added Al-Mg-Si alloy showed similar to those of β’-phase in Al-Mg-Si alloy without Ag and had different lattice spacings because of the effect of Ag. According to our careful analysis on obtained HRTEM images and SADPs, it includes more complicated crystal lattice of distorted hexagons.

HRTEM Study of Precipitates in Al-Mg-Si and Al-Mg-Ge Alloys

2006 ◽  
Vol 519-521 ◽  
pp. 221-226 ◽  
Author(s):  
Kenji Matsuda ◽  
Susumu Ikeno ◽  
Teruyoshi Munekata
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Metastable Phase ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Diffraction Technique

In this work, the crystal structure of the rod-shaped precipitate in aged Al -1.0 mass% Mg2Ge alloy at 523 K has been investigated by high resolution transmission electron microscopy (HRTEM), electron diffraction technique and energy dispersive X-ray spectroscopy (EDS). The rod-shaped precipitate in its alloy has showed the similar arrangement of bright dots in its HRTEM images and selected area diffraction pattern (SADP) to those of the b’-phase in Al-Mg2Si alloy. But a lattice constant of this precipitate in Al-Mg2Ge alloy was slightly larger than the b’-phase in Al-Mg2Si alloy. In addition, the new metastable phase has been found out in Al-Mg-Ge alloy.

HRTEM Investigation of Precipitates in Al-Zn-In-Mg-Ti-Ce Anode Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 1036-1039
Author(s):  
Jing Ling Ma ◽  
Jiu Ba Wen ◽  
Yan Fu Yan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Hexagonal Structure ◽  
Orientation Relation ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Scanning Electron

The precipitates of Al-5Zn-0.02In-1Mg-0.05Ti-0.5Ce (wt %) anode alloy were studied by scanning electron microscopy, X-ray microanalysis, high resolution transmission electron microscopy and selected area electron diffraction analyses in the present work. The results show that the alloy mainly contains hexagonal structure MgZn2 and tetragonal structure Al2CeZn2 precipitates. From high resolution transmission electron microscopy and selected area electron diffraction, aluminium, Al2CeZn2 and MgZn2 phases have [0 1 -1]Al|| [1 -10]Al2CeZn2|| [-1 1 0 1]MgZn2orientation relation, and Al2CeZn2 and MgZn2 phases have the [0 2 -1]Al2CeZn2|| [0 1 -10]MgZn2orientation relation.

scholarly journals MicroED: a versatile cryoEM method for structure determination

2018 ◽  
Vol 2 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Brent L. Nannenga ◽  
Tamir Gonen
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Electron Diffraction ◽  
Structure Determination ◽  
Materials Science ◽  
Electron Diffraction Data ◽  
Determination Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Micro-electron diffraction, or MicroED, is a structure determination method that uses a cryo-transmission electron microscope to collect electron diffraction data from nanocrystals. This technique has been successfully used to determine the high-resolution structures of many targets from crystals orders of magnitude smaller than what is needed for X-ray diffraction experiments. In this review, we will describe the MicroED method and recent structures that have been determined. Additionally, applications of electron diffraction to the fields of small molecule crystallography and materials science will be discussed.

Crystal structure and defects of Zr4Co4Si7 (V-phase) investigated by high resolution transmission electron microscope

1997 ◽  
Vol 12 (2) ◽  
pp. 377-384
Author(s):  
J. F. Mao ◽  
H. Q. Ye ◽  
X. G. Ning ◽  
L. L. He ◽  
D. Z. Yang
Keyword(s):  
Crystal Structure ◽  
Electron Microscope ◽  
High Resolution ◽  
Transmission Electron Microscope ◽  
Phase Structure ◽  
Structure Type ◽  
Image Simulation ◽  
Transmission Electron ◽  
Hrtem Observation ◽  
Coherent Interfaces

The results of high resolution transmission electron microscope (HRTEM) observation and image simulation show that Zr4Co4Si7 possesses the same structure type of Zr4Co4Ge7. Addition of Fe or Ni into the Zr4Co4Si7 compound, except that the dimensions changed slightly, does not change the lattice type and coordination in the crystal structure, maintaining the V-phase structure. Also, twins with coherent boundaries and partially coherent interfaces are observed. The image conditions of Zr4Co4Si7 and the structure differences between Zr4Co4Si7 and tetrahedral close-packed phases are also discussed.

Crystal structure and stacking faults of myristyl stearate identified by electron diffraction

1989 ◽  
Vol 47 ◽  
pp. 662-663
Author(s):  
W.P. Zhang ◽  
D.L. Dorset ◽  
J. Hanlon
Keyword(s):  
Crystal Structure ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Crystal Structures ◽  
Fourier Transforms ◽  
Stacking Faults ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Diffraction Patterns ◽  
Long Chain

Although a few X-ray crystal structures of normal-chain esters of long chain acids and short chain alcohols have been carried out, attention has been paid mostly to the long-spacings of waxes synthesized from longer chain alcohols. We have been interested in exploring the crystal structures of the more symmetric waxes via electron diffraction studies.Myristyl stearate thin crystals were epitaxially grown on benzoic acid by the method developed by Wittmann et al. Some samples with or without the presence of the nucleating substrates were annealed at 45°C for 4 hours on a Met tier FP82 hot stage. The thin crystals before or after annealing were examined with a JEOL JEM-100CX electron microscope operated at 100 kV, and selected area electron diffraction patterns from [100] and [110] directions were recorded on Kodak DEF-5 X-ray film. The calibration of the camera length was carried out with a gold Debye-Scherrer diagram. Models of molecular packing were scanned with an Optronics P-1000, and their Fourier transforms were calculated with a program in IMAGIC.

Comparative Studies of Magneto-Optical and Photocatalytic Properties of Magnetically Recyclable Spinel ZnFe2O4 Nanostructures by Combustion Methods

2019 ◽  
Vol 18 (02) ◽  
pp. 1850020 ◽  
Author(s):  
R. C. Sripriya ◽  
B. Vigneaswari ◽  
Victor Antony Raj
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Secondary Phase ◽  
Conventional Heating ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Phase Spinel ◽  
Improved Performance ◽  
The Comparative Study

Spinel ZnFe2O4 nanoparticles (NPs) were successfully synthesized by a simple microwave irradiation method (MIM) using glycine as the fuel. For the comparative study purpose, it was also prepared by conventional heating (CHM) method. Powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), high resolution scanning electron microscope (HR-SEM), high resolution transmission electron microscope (HR-TEM), energy dispersive X-ray (EDX) spectra, selected area electron diffraction (SAED) analysis showed that the samples were pure phase spinel ZnFe2O4 nanoparticles-like morphology without any other secondary phase impurity. UV-Visible diffuse reflectance spectra (DRS) and room temperature photoluminescence (PL) spectra were confirmed the optical bandgap ([Formula: see text] and defects state of the samples. The calculated [Formula: see text] values of the samples are 1.91[Formula: see text]eV and 2.08[Formula: see text]eV for ZnFe2O4-MIM and ZnFe2O4-CHM, respectively. Vibrating sample magnetometer (VSM) analysis show the Ms value is 37.66[Formula: see text]emu/g for ZnFe2O4-MIM, which is higher than ZnFe2O4-CHM (24.23 emu/g) sample, which confirm both the products showed superparamagnetic behavior. ZnFe2O4-MIM was found to have higher surface area than ZnFe2O4-CHM, which in turn leads to the improved performance toward the photocatalytic degradation (PCD) of 4-chlorophenol (4-CP) and it was found that the sample ZnFe2O4-MIM show higher PCD efficiency (91.43%) than ZnFe2O4-CHM (84.65%), also the samples show high activity, good reusability, remarkable stability and environmentally friendly materials for industrial and technological applications.

HRTEM Observation of the Age Hardening Precipitates in Mg-Gd-Sc Alloys, with Different Gd Concentrations

2011 ◽  
Vol 409 ◽  
pp. 335-338
Author(s):  
Takafumi Fujii ◽  
Kenji Matsuda ◽  
Tokimasa Kawabata ◽  
Susumu Ikeno
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Transmission Electron Microscope ◽  
Age Hardening ◽  
Number Density ◽  
Maximum Hardness ◽  
Β Phase ◽  
Transmission Electron ◽  
Hrtem Observation

High resolution transmission electron microscope (HRTEM) observations were performed to investigate the age hardening precipitates in Mg-Gd-Sc alloys. The maximum hardness of these alloys increased with Gd content. The precipitates with the features of β” phase and β’ phase in Mg-Gd alloy were observed in Mg-15Gd-6.4Sc and Mg-10Gd-6.4Sc alloys. Maximum hardness and number density of precipitate in Mg-15Gd-6.4Sc alloy were higher than that in Mg-10Gd-6.4Sc alloy, and the finer precipitates with higher number of density were contributed to the maximum hardness in Mg-Gd-Sc alloys.

TEM Observation of Metastable Phases in Aged Al-Mg-Ge Alloys

2010 ◽  
Vol 654-656 ◽  
pp. 930-933 ◽  
Author(s):  
Kenji Matsuda ◽  
Junya Nakamura ◽  
Keisuke Yamamoto ◽  
Tokimasa Kawabata ◽  
Yasuhiro Uetani ◽  
...  
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Relative Frequency ◽  
Metastable Phase ◽  
Metastable Phases ◽  
Aged Condition ◽  
Aging Behavior ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Energy Loss

The purpose of study is to investigate aging behavior, crystal structures of metastable phase and relative frequency of metastable phases in aged Al-Mg-Ge and Al-Mg-Ge-Si alloys using high resolution transmission electron microscope (HRTEM), energy dispersive X-ray spectroscopy (EDS) and electron energy-loss spectroscopy (EELS). Every alloy included rod-shaped precipitate which is the same as the typical metastable pahse, ’, in Al-Mg-Si alloy. Except to Mg-rich alloys, the Type-A precipitate, which is a typical metastable phase in the excess Si type Al-Mg-Si alloys and popular at over aged condition, was confirmed as a large rod-shaped precipitates in those alloys. This behavior is probably depends on the ratio of Mg/Ge. Also, Mg, Si and Ge were detected from the ’-phase in Al-Mg-Ge-Si alloy by EELS. This means that the ’-phase in Al-Mg-Ge-Si alloy consists of these 3 elements including Si, not just Ge to form metastable Mg2Ge.

Sign in / Sign up

Export Citation Format

Share Document