Polytypoids in high Tc thallium based superconducting materials

Several high Tc compounds containing Tl (thallium) were prepared starting from different initial compositions. Superconducting properties and the structure were determined for each sample. Electron diffraction and transmission electron microscopy showed the existence of polytypic high Tc compounds with the same a- and b-axes but different c-axis values. The c-axis appears to increase approximately in integral multiples of 0.15 nm with varying composition and is associated with the insertion of Cu–Ca or Cu–Tl layers in each unit cell. Several random stacking faults were also noted, which give rise to diffuse streaking in the electron diffraction pattern.

Download Full-text

Microstructure of Bonding Interface in Explosively Welded Metal/Ceramic Clad

Materials Science Forum ◽

10.4028/www.scientific.net/msf.638-642.3775 ◽

2010 ◽

Vol 638-642 ◽

pp. 3775-3780 ◽

Cited By ~ 1

Author(s):

Seiichiro Ii ◽

Chihiro Iwamoto ◽

Shinobu Satonaka ◽

Kazuyuki Hokamoto ◽

Masahiro Fujita

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Silicon Nitride ◽

Electron Diffraction ◽

Electron Diffraction Pattern ◽

Explosive Welding ◽

Bonding Interface ◽

X Ray ◽

Transmission Electron ◽

Metal Ceramic

Bonding interface in aluminum (Al) and silicon nitride (Si3N4) clad fabricated by explosive welding has been investigated by transmission electron microscopy (TEM). The nanocrystalline region was clearly observed at the interface between Al and Si3N4. Electron diffraction pattern and energy dispersive X-ray spectroscopy (EDS) measurements across the interface revealed that this nanocrystalline region consist of the only aluminum.

Download Full-text

Analysis of SiC Islands Formation during First Steps of Si Carbonization Process

Materials Science Forum ◽

10.4028/www.scientific.net/msf.483-485.555 ◽

2005 ◽

Vol 483-485 ◽

pp. 555-558 ◽

Cited By ~ 2

Author(s):

David Méndez ◽

A. Aouni ◽

Daniel Araújo ◽

Etienne Bustarret ◽

Gabriel Ferro ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Electron Diffraction ◽

Carbon Source ◽

Electron Diffraction Pattern ◽

Attenuated Total Reflectance ◽

Total Reflectance ◽

Carbonization Process ◽

Transmission Electron ◽

Three Samples

The effect of the temperature at which the carbon source is introduced in the reactor on the early stages of the carbonization process is analyzed here. Three samples heated up to 1150°C with propane introduction temperatures (Tintro) of 725, 1030 and 1100°C are analyzed by transmission electron microscopy and attenuated total reflectance. The size of the SiC nuclei increases with Tintro. There is also an effect on the strain of the resulting carbonization layer. The electron diffraction pattern of the sample with the highest Tintro shows a fully relaxed 3C-SiC layer, while no evidence of SiC relaxation is present in low Tintro samples where the SiC islands seems to be pseudomorphic.

Download Full-text

Epitaxial Growth of SrTiO3 Thin Films on TiN/Si Substrates Using RF Sputtering

MRS Proceedings ◽

10.1557/proc-0966-t07-21 ◽

2006 ◽

Vol 966 ◽

Cited By ~ 1

Author(s):

Chun Wang ◽

Mark H Kryder

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Transmission Electron Microscopy ◽

High Resolution ◽

Electron Diffraction ◽

Electron Diffraction Pattern ◽

Rf Sputtering ◽

Epitaxial Relationship ◽

Si Substrates ◽

Transmission Electron

ABSTRACTEpitaxial SrTiO3 (001) thin films with a TiN template layer have been deposited on Si(001) single crystal substrates by RF sputtering. The deposited SrTiO3 films show a surface with roughness of 0.66nm. The orientation relationship was determined to be SrTiO3(001)[110]∥TiN(001)[110]∥Si(001)[110]. The microstructure and interface of the multilayer was studied using high resolution transmission electron microscopy (TEM). The electron diffraction pattern confirmed the epitaxial relationship between each layer.

Download Full-text

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.519-521.221 ◽

2006 ◽

Vol 519-521 ◽

pp. 221-226 ◽

Cited By ~ 9

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.

Download Full-text

TEMTUTOR - a Teaching Multimedia Program for TEM

Microscopy and Microanalysis ◽

10.1017/s1431927600012691 ◽

1997 ◽

Vol 3 (S2) ◽

pp. 1161-1162

Author(s):

V.-T. Kuokkala ◽

T.K. Lepistö

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Electron Diffraction ◽

Stacking Faults ◽

Teaching Tool ◽

Formation Processes ◽

Multimedia Program ◽

Transmission Electron ◽

Hands On ◽

Diffraction Patterns

Teaching of transmission electron microscopy usually includes both lectures on the contrast theories, electron diffraction, etc., and practical hands-on operation of the microscope. The number of students attending the lectures is normally unlimited, but at the microscope, only a few persons can work at the same time. Since the microscopes are expensive, it would be of a great help if cheaper 'training' microscopes with basic imaging and diffraction capabilities were available. These functions, in fact, can quite easily be realized with fast personal computers and work stations, where the simulation of transmission electron micrographs and related diffraction patterns can help the student better understand the image formation processes. Adding text, audio and video help capabilities to the program, it can be made an efficient supplemental teaching tool.TemTutor for Windows is based on microScope for Windows, which is a BF/DF TEM micrograph simulation program for dislocations and stacking faults.

Download Full-text

Twinning and defects in N-Nb2O5

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768100003657 ◽

2000 ◽

Vol 56 (5) ◽

pp. 780-784 ◽

Cited By ~ 2

Author(s):

Franziska E. Rohrer ◽

Ann-Kristin Larsson

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

High Resolution ◽

Electron Diffraction ◽

Stacking Faults ◽

Twin Plane ◽

The Other ◽

Selected Area Electron Diffraction ◽

Transmission Electron ◽

Block Arrangement

N-Nb2O5 [C2/m (No. 12), a = 28.51, b = 3.830 and c = 17.48 Å, and β = 124.8°] has been investigated by means of selected-area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM). N-Nb2O5 is domain twinned, with the twin plane perpendicular to the c* axis. The domains are rather small and the domain twinning can sometimes be best explained as stacking faults. A second type of coherent twinning at an angle of 90° to the other two domain directions was also found. These domains are linked together by areas containing blocks of different sizes, similar to the disordered block arrangement observed in M-Nb2O5.

Download Full-text

PH Dependence of the Size and Shape of the Gold Nanoparticles Prepared by Macromolecules

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.634-638.2228 ◽

2013 ◽

Vol 634-638 ◽

pp. 2228-2231

Author(s):

Chun Rong Wang ◽

Xian Zai Yan ◽

Li Li Yu

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Gold Nanoparticles ◽

Electron Diffraction ◽

Electron Diffraction Pattern ◽

Ph Dependence ◽

Gold Nanostructures ◽

Size And Shape ◽

Transmission Electron ◽

Shape Changes

The eﬀect of the pH of the preparing solution on the size and shape of gold nanoparticles was studied in the solution containing soybean peptides or β-cyclodextrin (β-CD) as reducing agent. The resulting gold nanostructures were characterized by transmission electron microscopy (TEM), XRD and UV-vis spectra. Different shape of gold nanoparticles such as nanoplates, networked nanowires and spheres were prepared by changing the pH of solution. Electron diffraction pattern showed that the shape changes from plate or network to sphere as the pH of solution is increasing.

Download Full-text

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100175259 ◽

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).

Download Full-text

Transmission Electron Microscopy of Epitaxial silicides grown by ultra high vacuum deposition

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100154287 ◽

1989 ◽

Vol 47 ◽

pp. 462-463

Author(s):

D. Loretto ◽

J. M. Gibson ◽

S. M. Yalisove

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Electron Diffraction ◽

High Vacuum ◽

High Energy ◽

Energy Electron ◽

Ultra High Vacuum ◽

Ex Situ ◽

Transmission Electron

The silicides CoSi2 and NiSi2 are both metallic with the fee flourite structure and lattice constants which are close to silicon (1.2% and 0.6% smaller at room temperature respectively) Consequently epitaxial cobalt and nickel disilicide can be grown on silicon. If these layers are formed by ultra high vacuum (UHV) deposition (also known as molecular beam epitaxy or MBE) their thickness can be controlled to within a few monolayers. Such ultrathin metal/silicon systems have many potential applications: for example electronic devices based on ballistic transport. They also provide a model system to study the properties of heterointerfaces. In this work we will discuss results obtained using in situ and ex situ transmission electron microscopy (TEM).In situ TEM is suited to the study of MBE growth for several reasons. It offers high spatial resolution and the ability to penetrate many monolayers of material. This is in contrast to the techniques which are usually employed for in situ measurements in MBE, for example low energy electron diffraction (LEED) and reflection high energy electron diffraction (RHEED), which are both sensitive to only a few monolayers at the surface.

Download Full-text