A Study on Equal-Thickness Fringes in a Silicon Crystal by Means of an X-ray Video Imaging Device

Abstract

We have carried out pseudopotential calculations of the effect of mixing in semiconductor superlattices between bulk states derived from the conduction band minimum at thecentreof the bulk Brillouinzoneand thoseoftheXminimaat thezone edges. Wepresent a systematic account of (i) the strength of this coupling in GaAh4I.4~ superlattices as a function of the layer widths, (ii) the variation as a function of layer width of the magnitude of the energy gap that occurs when the levels derived from different bulk valleys cross, (iii) the changeoftheoscillatorstrengthofthe transitionacross thesuperlattice gapasafunction of the separation of the interacting levels, and (iv) the magnitude of the effect of strain on valley mixing.

X-ray diffraction

“…An investigator should be aware of its effect on intensities before beginning X-ray analysis. The choice of a line sensitive to isomorphic replacement can allow one however to determine its extent (138,196,322).…”

“…Many systems have been described for the display of X-ray topographic images (67, 138,201,203,227,250,274), one having a resolving capability of better than and Lardear (260) have reported on the use of a fluorescent screen with a new industrial X-ray film for which exposures using MoKa radiation are cut by a factor of ten. A special thin fluorescent screen optimized for CuKq radiation was used for Weissenberg and Debye-Scherrer cameras and reduced exposure times by a factor of two.…”