Reciprocal Lattice & Diffraction Crystallography H. K. D. H. Bhadeshia Reciprocal Lattice & Diffraction
Weiss Zone Rule proven!
Cubic P, section of reciprocal lattice normal to [001]
Cubic P, section of reciprocal lattice normal to [110]
Cubic P, section of reciprocal lattice normal to [111]
For 100 keV accelerating voltage, the wavelength of electrons is 0 For 100 keV accelerating voltage, the wavelength of electrons is 0.0037 nm. If the d spacing is 0.2 nm, then the Bragg angle is just 0.5° Ewald sphere has a large diameter in reciprocal space.
Cubic P Cubic F
Cubic P Cubic F
Cubic P Cubic F
Lattice: face-centred cubic Motif: Si at 0,0,0 Si at 1/4,1/4,1/4 3/4 1/4 3/4 1/4 3/4 1/4 3/4 1/4 Lattice: face-centred cubic Motif: Si at 0,0,0 Si at 1/4,1/4,1/4
diffraction from thin crystals
100 nm thick foil 20 nm thick foil
[111] [0.99 0.99 1.02]
(R. Herring)