Crystallography of hexagonal germanium

Abstract

When a thin foil of amorphous germanium is crystallized by a pulsed laser beam¹, an electron beam or by vacuum annealing², the resulting polycrystalline matrix has the diamond cubic transmission electron diffraction pattern shown in Fig. 1. However, we have recently obtained crystal lattice images from some of the crystals in this polycrystalline matrix which had interplanar angles that were not characteristic of a diamond cubic structure. We now resolve this problem by demonstrating that crystals in the polycrystalline matrix had either a hexagonal or a diamond cubic crystal structure.