scholarly journals Experimental Techniques for the Measurement of Diffusion Coefficients

1990 ◽  
pp. 269-286 ◽  
Author(s):  
Steven J. Rothman
Keyword(s):  
Diffusion Coefficients ◽  
Experimental Techniques

Self-Diffusion in Molten Lead Bromide

1968 ◽  
Vol 23 (2) ◽  
pp. 239-241 ◽  
Author(s):  
C.-A. Sjöblom ◽  
J. Andersson
Keyword(s):  
Diffusion Coefficients ◽  
Transport Number ◽  
The Self ◽  
Experimental Techniques ◽  
New Formalism ◽  
Self Diffusion ◽  
Lead Bromide ◽  
Molten Lead ◽  
Calculated Quantity

The self-diffusion coefficients of both ions in molten PbBr2 have been measured with a modification of the porous-frit technique1-3. The results can be described with Arrhenius relations:DPb=7.4 × 10-4 exp(-6500±900)/RT (380-540°C),DBr=8.3 × 10-4 exp(-6100±700)/RT (380-555°C).D is expressed in cm2s-1, R in cal · mole-1 degree-1 and T in degrees Kelvin. The relative merits of different experimental techniques are discussed and a comparison between the (experimental) external transport number and the corresponding calculated quantity using Laity’s “new formalism” is made.

Interlayer mixing in GaAs/AlxGa1-xAs heterostructures as a result of Se+ ion implantation

1988 ◽  
Vol 46 ◽  
pp. 908-909
Author(s):  
E.G. Bithell ◽  
W.M. Stobbs
Keyword(s):  
Ion Implantation ◽  
Diffusion Coefficients ◽  
Dark Field ◽  
Atomic Mass ◽  
Composition Profile ◽  
Semiconductor Heterostructures ◽  
Transmission Electron ◽  
Microscope Images ◽  
Damage Process ◽  
Electron Energy Loss

It is well known that the microstructural consequences of the ion implantation of semiconductor heterostructures can be severe: amorphisation of the damaged region is possible, and layer intermixing can result both from the original damage process and from the enhancement of the diffusion coefficients for the constituents of the original composition profile. A very large number of variables are involved (the atomic mass of the target, the mass and energy of the implant species, the flux and the total dose, the substrate temperature etc.) so that experimental data are needed despite the existence of relatively well developed models for the implantation process. A major difficulty is that conventional techniques (e.g. electron energy loss spectroscopy) have inadequate resolution for the quantification of any changes in the composition profile of fine scale multilayers. However we have demonstrated that the measurement of 002 dark field intensities in transmission electron microscope images of GaAs / AlxGa1_xAs heterostructures can allow the measurement of the local Al / Ga ratio.

Experimental techniques in neutron scattering

1972 ◽  
Vol 14 (7) ◽  
pp. 255-268
Author(s):  
P. Mériel
Keyword(s):  
Neutron Scattering ◽  
Experimental Techniques
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