Cesium diffusion at a tungsten surface

1969 ◽  
Vol 47 (6) ◽  
pp. 657-663 ◽  
Author(s):  
H. M. Love ◽  
H. D. Wiederick
Keyword(s):  
Activation Energy ◽  
Diffusion Coefficient ◽  
Single Crystal ◽  
Surface Diffusion ◽  
Diffusion Processes ◽  
Bulk Diffusion ◽  
Photoelectric Method ◽  
Surface Diffusion Coefficient ◽  
Tungsten Surface ◽  
The Mean

The diffusion of cesium at the surface of tungsten ribbons has been measured under ultrahigh vacuum conditions. A photoelectric method was used to determine the cesium surface concentrations which were in the range from about 5 × 10−4 to 2 × 10−2 monolayers. The measured changes in concentration with time and temperature were consistent, for a polycrystalline ribbon, with two bulk diffusion processes with activation energies of 1.7 ± 0.3 eV and 0.17 ± 0.03 eV. For a single crystal, it was found that limited bulk diffusion occurred with an activation energy of 0.21 ± 0.02 eV. The mean surface diffusion coefficient for cesium on a (110) tungsten surface over the temperature range from 550 °K to 850 °K was given by D = (0.23 ± 0.10 cm2 s−1) exp [−(0.57 ± 0.02 eV)/kT].

Surface Diffusion of Sulfur on Nickel (110) and the Effect of Carbon on the Diffusivity

1992 ◽  
Vol 280 ◽  
Author(s):  
Barbara Ladna ◽  
Howard K. Birnbaum
Keyword(s):  
Activation Energy ◽  
Diffusion Coefficient ◽  
Surface Diffusion ◽  
Half Plane ◽  
Auger Electron ◽  
Arrhenius Plot ◽  
Electron Spectrometer ◽  
Plane Source ◽  
Surface Diffusion Coefficient ◽  
Diffusion Profiles

ABSTRACTThe surface diffusion coefficient of sulfur on the (110) surface of nickel was determined at temperatures of 623, 673 and 723 K by measurement of surface diffusion profiles using an Auger Electron Spectrometer. A half-plane monolayer of segregated sulfur was used as a source and the analysis was done by a Boltzmann-Matano method. The activation energy for surface diffusion of sulfur was determined to be about 106 kJ/mol and pre-exponential Do to be about 6×10-3 m2/s from the Arrhenius plot of D versus 1/T. The presence of carbon on the surface of nickel was shown to decrease the surface diffusion of sulfur. Also, the mechanism of spreading from the half-plane source changed from a classic surface diffusion on clean surfaces to a linear mobility of the sulfur-carbon interface on surfaces covered with carbon.

A technique for the measurement of surface diffusion coefficient and activation energy of Ge adatom on Si(001)

2004 ◽  
Vol 95 (11) ◽  
pp. 6065-6071 ◽  
Author(s):  
H. J. Kim ◽  
Z. M. Zhao ◽  
J. Liu ◽  
V. Ozolins ◽  
J. Y. Chang ◽  
...  
Keyword(s):  
Activation Energy ◽  
Diffusion Coefficient ◽  
Surface Diffusion ◽  
Surface Diffusion Coefficient

scholarly journals FLATTENING OF A SCRATCH ON SINGLE CRYSTAL ICE SURFACE

Anales AFA ◽  
2020 ◽  
Vol 31 (3) ◽  
pp. 86-92
Author(s):  
G. Aguirre Varela ◽  
◽  
D. Stoler Flores ◽  
P.I. Achával ◽  
C.L. Di Prinzio
Keyword(s):  
Diffusion Coefficient ◽  
Single Crystal ◽  
Surface Diffusion ◽  
Silica Gel ◽  
Three Dimensional ◽  
Confocal Microscope ◽  
Surface Diffusion Coefficient ◽  
Diffusion Transport ◽  
Ice Surface ◽  
Activated Silica Gel

The surface of a monocrystalline ice sample was observed at −5 ◦C (268 K). For which it was superficially polished and allowed to evolve in the presence of activated silica gel for three hours. The evolution of a depression was studied using three-dimensional micrographs obtained with an Olympus OLS4000 LEXT confocal microscope. A predominance of surface diffusion transport was found in the evolution of the depression. This is based both on the value obtained for the surface diffusion coefficient, as well as on the values found for the exponents corresponding to the evolution of the depth of the well and its width.

Reduction of the Defect Density in a-Si:H Deposited at ≤250°C

1993 ◽  
Vol 297 ◽  
Author(s):  
Hitoshi Nishio ◽  
Gautam Ganguly ◽  
Akihisa Matsuda
Keyword(s):  
Diffusion Coefficient ◽  
Amorphous Silicon ◽  
Surface Diffusion ◽  
Film Growth ◽  
Defect Density ◽  
Hydrogenated Amorphous Silicon ◽  
Device Fabrication ◽  
Surface Diffusion Coefficient ◽  
Hydrogenated Amorphous ◽  
Substrate Temperatures

We present a method to reduce the defect density in hydrogenated amorphous silicon (a-Si:H) deposited at low substrate temperatures similar to those used for device fabrication . Film-growth precursors are energized by a heated mesh to enhance their surface diffusion coefficient and this enables them to saturate more surface dangling bonds.

Temperature dependence of the surface diffusion coefficient of K atoms on Pd{111} measured with PEEM

1996 ◽  
Vol 352-354 ◽  
pp. 546-551 ◽  
Author(s):  
M. Šnábl ◽  
M. Ondřejček ◽  
V. Cháb ◽  
W. Stenzel ◽  
H. Conrad ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Temperature Dependence ◽  
Surface Diffusion ◽  
Surface Diffusion Coefficient

scholarly journals The surface diffusion coefficient of Al2O3 obtained by free sintering.

1977 ◽  
Vol 85 (980) ◽  
pp. 185-189 ◽  
Author(s):  
Wazo KOMATSU ◽  
Yusuke MORIYOSHI ◽  
S. K. MOON ◽  
Hideaki KAMATA ◽  
Shigeyuki KURASHIMA
Keyword(s):  
Diffusion Coefficient ◽  
Surface Diffusion ◽  
Surface Diffusion Coefficient
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