scholarly journals Direct observation of electronic inhomogeneities induced by point defect disorder in manganite films

2010 ◽  
Vol 107 (11) ◽  
pp. 113903 ◽  
Author(s):  
M. Sirena ◽  
A. Zimmers ◽  
N. Haberkorn ◽  
E. Kaul ◽  
L. B. Steren ◽  
...  
Keyword(s):  
Point Defect ◽  
Direct Observation ◽  
Defect Disorder

Thermal conductivity of ThO2: Effect of point defect disorder

2021 ◽  
Vol 129 (7) ◽  
pp. 075102
Author(s):  
W. Ryan Deskins ◽  
Ahmed Hamed ◽  
Tomohisa Kumagai ◽  
Cody A. Dennett ◽  
Jie Peng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Point Defect ◽  
Defect Disorder

scholarly journals Point defect disorder in high-temperature solution grown Sr 6 Tb 0.94 Fe 1.06 (BO 3 ) 6 single crystals

2018 ◽  
Vol 264 ◽  
pp. 91-97 ◽  
Author(s):  
M. Velázquez ◽  
S. Péchev ◽  
M. Duttine ◽  
A. Wattiaux ◽  
C. Labrugère ◽  
...  
Keyword(s):  
High Temperature ◽  
Point Defect ◽  
Single Crystals ◽  
High Temperature Solution ◽  
Defect Disorder ◽  
Temperature Solution

Self-interstitials have never been observed in crystalline Si. How about amorphous Si?

2000 ◽  
Vol 609 ◽  
Author(s):  
Sjoerd Roorda
Keyword(s):  
Distribution Function ◽  
High Resolution ◽  
Point Defect ◽  
Radial Distribution Function ◽  
Direct Observation ◽  
Crystalline Silicon ◽  
Direct Detection ◽  
Before And After ◽  
Amorphous Si ◽  
Diffusion Behaviour

ABSTRACTIn the early days of point defect studies in electron irradiated crystalline silicon, it was surmised that the Si self-interstitial is highly mobile even at 4 K and escapes direct detection. The existence of self-interstitials has of course been confirmed through the diffusion behaviour of a range of impurities and the direct observation of larger interstitial-type clusters. Against this background, the direct observation of self-interstitials in amorphous Si would seem next to impossible. Yet just such an observation may have been made recently, through a comparison of the high-resolution radial distribution function of pure amorphous Si before and after thermal anneal and that of crystalline Si.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

Application of a Simple Cold Stub to the Direct Observation of Frozen Hydrated Sand

1973 ◽  
Vol 31 ◽  
pp. 212-213
Author(s):  
John M. Wehrung ◽  
Richard J. Harniman
Keyword(s):  
United States ◽  
Surface Water ◽  
Direct Observation ◽  
Controlled Study ◽  
Clay Particles ◽  
Organic Debris ◽  
Rock Formations ◽  
Water Tables ◽  
Permeable Rock ◽  
Natural Means

Water tables in aquifer regions of the southwest United States are dropping off at a rate which is greater than can be replaced by natural means. It is estimated that by 1985 wells will run dry in this region unless adequate artificial recharging can be accomplished. Recharging with surface water is limited by the plugging of permeable rock formations underground by clay particles and organic debris.A controlled study was initiated in which sand grains were used as the rock formation and water with known clay concentrations as the recharge media. The plugging mechanism was investigated by direct observation in the SEM of frozen hydrated sand samples from selected depths.

Direct Observation of the Diffusionless β → β + ω Transformation in Titanium Alloys

1971 ◽  
Vol 29 ◽  
pp. 122-123
Author(s):  
N. E. Paton ◽  
D. de Fontaine ◽  
J. C. Williams
Keyword(s):  
Electron Microscope ◽  
Titanium Alloys ◽  
Direct Observation ◽  
Dark Field ◽  
X Ray Diffraction ◽  
Resistivity Measurements ◽  
Selected Area Electron Diffraction ◽  
Ti Alloys ◽  
Thin Foils ◽  
Field Device

The electron microscope has been used to study the diffusionless β → β + ω transformation occurring in certain titanium alloys at low temperatures. Evidence for such a transformation was obtained by Cometto et al by means of x-ray diffraction and resistivity measurements on a Ti-Nb alloy. The present work shows that this type of transformation can occur in several Ti alloys of suitable composition, and some of the details of the transformation are elucidated by means of direct observation in the electron microscope.Thin foils were examined in a Philips EM-300 electron microscope equipped with a uniaxial tilt, liquid nitrogen cooled, cold stage and a high resolution dark field device. Selected area electron diffraction was used to identify the phases present and the ω-phase was imaged in dark field by using a (101)ω reflection. Alloys were water quenched from 950°C, thinned, and mounted between copper grids to minimize temperature gradients in the foil.

A New 1000kv Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 100-101
Author(s):  
J.L. Williams ◽  
K. Heathcote ◽  
E.J. Greer
Keyword(s):  
Electron Microscope ◽  
Direct Observation ◽  
High Voltage ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Specimen Thickness ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
Dynamic Experiments ◽  
Conventional Instrument

High Voltage Electron Microscope already offers exciting experimental possibilities to Biologists and Materials Scientists because the increased specimen thickness allows direct observation of three dimensional structure and dynamic experiments on effectively bulk specimens. This microscope is designed to give maximum accessibility and space in the specimen region for the special stages which are required. At the same time it provides an ease of operation similar to a conventional instrument.

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