scholarly journals Особенности структуры германия, обработанного в планетарной мельнице

2020 ◽  
Vol 62 (10) ◽  
pp. 1597
Author(s):  
Т.А. Гордеева ◽  
Д.А. Овсянников ◽  
М.Ю. Попов ◽  
Б.А. Кульницкий ◽  
В.Д. Бланк
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Diamond Powder ◽  
Planetary Mill ◽  
Transmission Electron ◽  
Germanium Powder

In this work high-resolution transmission electron microscopy (HRTEM) studies of germanium powder obtained as a result of processing in a planetary mill in the presence of (5-25%) of diamond powder have been performed. As a result of processing sample contains twins on {111} plane and packaging defects in germanium. Phase 9R was detected in which the following sequence of layers takes place: ...BABCBCACA... In some particles, there was a partial or complete phase transition of GeI → GeIV and GeI → GeIII.

Electron microscopy of the commensurate-incommensurate phase transition with the discommensuration network in 1T-TaS2

1990 ◽  
Vol 48 (4) ◽  
pp. 168-169
Author(s):  
Takashi Ishiguro ◽  
Hiroshi Sato
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Phase Transitions ◽  
High Resolution ◽  
Low Temperature ◽  
Transmission Electron ◽  
Continuous Rotation ◽  
T Phase ◽  
New Phase

Phase transitions of lT-TaS2 both on cooling from the incommensurate (IC) phase and on heating from the commensurate (C) phase are investigated by high resolution (HR) transmission electron microscopy because phase transitions are strongly hysteretic. The phases which had been identified were Normal(T>543K,no modurated wave, the Cdl2 type of structure, ao=0.336nm co=0.590nm), IC(354K< T< 543K), NC(non-commensurate or nearly commensurate, 185K<T<353K) and C(T<K). On heating from the C phase, the new phase called the T phase (nearly commensurate triclinic ) appears between 200K and 280K, and that has the discommensuration (DC) network. The HR observations at low temperature reveal both the three dimentional structure of the C phase and the DC network structure of the T phase.On cooling from the IC phase, the structure of the NC phase is essentially incommensurate in the basal plane and a continuous rotation of the moduration direction towards the C phase occurs.

HREM study of ferroelectric domain wall in barium titanate

1994 ◽  
Vol 52 ◽  
pp. 566-567
Author(s):  
Laurent. Normand ◽  
Alain. Thorel ◽  
Yvan. Montardi
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Barium Titanate ◽  
Domain Walls ◽  
Ferroelectric Phase ◽  
Ferroelectric Domain ◽  
Transmission Electron ◽  
The One

This study focuses on High Resolution Transmission Electron Microscopy of barium titanate in its tetragonal ferroelectric phase, and especially on the structure of domain walls. This phase is stable between about 0 °C and 130 °C. During cooling, at 130 °C barium titanate changes from a cubic parraelectric phase to a tetragonal ferroelectric phase. In this phase the spontaneous polarisation is along one of the six [001] pseudo-cubic directions. Two types of domains can be formed during the phase transition :90° and 180° domains. In 90° domains the polarisation is at 90° from the polarisation of the next domain (exactly 2* ArcTan(a/c) if a and c are the lattice parameters). For these domains the domain walls are <110< type planes ; In 180° domains the polarisation is at 180° from the one in the next domain. 180° domain walls are <100< type plane and are assumed to be purely ferroelectric.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

Microstructure of laser-irradiated, conducting Kapton polyimide

1995 ◽  
Vol 53 ◽  
pp. 502-503
Author(s):  
D. L. Callahan ◽  
Z. Ball ◽  
H. M. Phillips ◽  
R. Sauerbrey
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Film Surface ◽  
Cross Sectional ◽  
General Utility ◽  
Transmission Electron ◽  
Considerable Debate ◽  
Potential Applications

Ultraviolet laser-irradiation can be used to induce an insulator-to-conductor phase transition on the surface of Kapton polyimide. Such structures have potential applications as resistors or conductors for VLSI applications as well as general utility electrodes. Although the percolative nature of the phase transformation has been well-established, there has been little definitive work on the mechanism or extent of transformation. In particular, there has been considerable debate about whether or not the transition is primarily photothermal in nature, as we propose, or photochemical. In this study, cross-sectional optical microscopy and transmission electron microscopy are utilized to characterize the nature of microstructural changes associated with the laser-induced pyrolysis of polyimide.Laser-modified polyimide samples initially 12 μm thick were prepared in cross-section by standard ultramicrotomy. Resulting contraction in parallel to the film surface has led to distortions in apparent magnification. The scale bars shown are calibrated for the direction normal to the film surface only.

scholarly journals Direct TEM observation of the “acanthite α-Ag2S–argentite β-Ag2S” phase transition in a silver sulfide nanoparticle

2019 ◽  
Vol 1 (4) ◽  
pp. 1581-1588 ◽  
Author(s):  
S. I. Sadovnikov ◽  
E. Yu. Gerasimov
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Silver Sulfide ◽  
Transmission Electron ◽  
Silver Sulfide Nanoparticles ◽  
Microscopy Method ◽  
Electron Microscopy Method ◽  
First Time

For the first time, the α-Ag2S (acanthite)–β-Ag2S (argentite) phase transition in a single silver sulfide nanoparticles has been observed in situ using a high-resolution transmission electron microscopy method in real time.

Improved quantification of curvature in high-resolution transmission electron microscopy lattice fringe micrographs of soots

Carbon ◽  
2017 ◽  
Vol 117 ◽  
pp. 174-181 ◽  
Author(s):  
Chang’an Wang ◽  
Thomas Huddle ◽  
Chung-Hsuan Huang ◽  
Wenbo Zhu ◽  
Randy L. Vander Wal ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Lattice Fringe ◽  
Transmission Electron
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