Diffraction spots mineral

All diffraction spots in the aurichalcite mineral calcined at 400°C (Figure 4b) could be attributed to ZnO, except for four weak spots with a d-spacing of 0.192 nm. These spots matched well the Cu0 ll2 reflections with a reported value of d = 0.195 nm (6). Crystalline CuO was found to be present at this stage by XRD, as seen from Figure 3c. 

Figure 5b. Mineral aurichalcite calcined at 350 C for 4 hours. Schematic diagram showing epitaxial registry and similarities of d-spacinqs for the most intense aurichalcite and ZnO diffraction spots, n = ZnO with [3031] zone axis, ZnO with [1010] zone axis, and Q " aurichalcite near [101] zone axis. A = aurichalcite.

For the H layer the two mechanisms suggested give the same type of disorder and, correspondingly, all the reciprocal-lattice rows with both k and odd (valid separately for the H sublattice and the H lattice) will consist of continuous diffraction streaks parallel to a. In the reciprocal T lattice the spots with both k and odd are less sharp and connected by the streaks, whereas the remaining lattice rows contain distinct diffraction spots. Thus, a partial disorder of the T layer, with shifts of hxsubcei/2, occurs in the layered structure of this mineral. Diffraction records are not sufficient to indicate the role of the disorder in the T layers with the shifts of hx/3. 

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