Prediction of holz pattern shifts in convergent beam diffraction

✍ Scribed by Jackson, A. G.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1987
• Tongue: English
• Weight: 283 KB
• Volume: 5
• Category: Article
• ISSN: 0741-0581
• DOI: 10.1002/jemt.1060050408

✦ Synopsis

In general, diffraction patterns from the higher-order Laue zones are shifted with respect to the zero-order pattern. Expressions for the shift (t) have been derived in terms of the indices [u, u, w ] of a zone, the interplanar spacing (M, and a reciprocal lattice vector [ g L (hkt)] in a holz. The resulting vector possesses the direction o f t in terms of a zolz reciprocal lattice vector and has a magnitude which is a fraction of that of the zolz vector. Hence, the calculation o f t allows quantitative determination of the location of specific planes in a holz with respect to the zolz, thus simplifying the determination of plane indices consistent with those used in the zolz. The expressions for determining t for cubic, hexagonal close-packed (hcp), tetragonal, orthorhombic, and monoclinic crystal types are presented in a table and, when applied, allow calculation o f t expressed as a fraction of a zolz vector. An example for graphite is presented to illustrate the use of the equation, and t vectors for several zones for the simple cubic system are tabulated.

Electron diffraction, Laue zones, Holz patterns