Measurement of atomic sodium and potassium diffusion coefficients

1984 ◽  
Vol 81 (11) ◽  
pp. 5125-5130 ◽  
Author(s):  
Joel A. Silver
Keyword(s):  
Diffusion Coefficients ◽  
Atomic Sodium ◽  
Sodium And Potassium

scholarly journals Plasma Dynamics in Mercury’s Magnetosphere

2005 ◽  
Vol 13 ◽  
pp. 67-69
Author(s):  
Wing-Huen Ip
Keyword(s):  
Solar Wind ◽  
Space Weather ◽  
Optical Observations ◽  
Surface Plasma ◽  
Plasma Dynamics ◽  
Weather Effects ◽  
Interaction Processes ◽  
Atomic Sodium ◽  
Sodium And Potassium

AbstractMercury is in all sense of the words still Terra Incognito, its magnetosphere is hence little known. The only source of knowledge came from the in-situ measurements by the Mariner 10 close encounters in 1974. This has been complemented since by ground-based observations of the atomic sodium and potassium emissions in the vicinity of the planetary disk. This series of optical observations has produced intriguing evidence of magnetospheric and/or solar wind effects on the surface-plasma interaction processes. In this review we will describe the current theories of the corresponding space weather effects.

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.

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