Direct observation of the atomic structure of W {100} surfaces

1979 ◽  
Vol 30 (12) ◽  
pp. 767-770 ◽  
Author(s):  
T.T. Tsong ◽  
John Sweeney
2000 ◽  
Vol 6 (4) ◽  
pp. 358-361 ◽  
Author(s):  
Shigeo Arai ◽  
Susumu Tsukimoto ◽  
Shunsuke Muto ◽  
Hiroyasu Saka

AbstractAn experimental high-resolution image of a solid–liquid interface of solid Si and liquid Al–Si alloy has been compared with theoretical images obtained by computer simulation. It has been concluded that the solid–liquid interface has a transition layer, the structure of which is compatible with the 1 × 1 Si-{111} surface.


2012 ◽  
Vol 15 (6) ◽  
pp. 707-712 ◽  
Author(s):  
H. Yamazaki ◽  
M. Yoshiki ◽  
R. Takaishi ◽  
S. Takeno

2000 ◽  
Vol 6 (4) ◽  
pp. 358-361 ◽  
Author(s):  
Shigeo Arai ◽  
Susumu Tsukimoto ◽  
Shunsuke Muto ◽  
Hiroyasu Saka

Abstract An experimental high-resolution image of a solid–liquid interface of solid Si and liquid Al–Si alloy has been compared with theoretical images obtained by computer simulation. It has been concluded that the solid–liquid interface has a transition layer, the structure of which is compatible with the 1 × 1 Si-{111} surface.


Author(s):  
R. W. Anderson ◽  
D. L. Senecal

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.


Author(s):  
John M. Wehrung ◽  
Richard J. Harniman

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.


Author(s):  
N. E. Paton ◽  
D. de Fontaine ◽  
J. C. Williams

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.


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