LabAdviser/314/Microscopy 314-307/SEM/Nova/Transmission Kikuchi diffraction: Difference between revisions

Figures 8 and 9 show the IPFZ maps overlaid with pattern quality for temperatures varying from 20°C to 900°C. A preliminary investigation of the Au film at room temperature revealed a bimodal nanostructure, with the presence of small grains with size in the range of 30 nm and large grains with size in the 150 nm range. The latter ones showed a strong [111] out-of-plane texture. During heating, the [111] grains tended to grow faster than the [110] and [100] ones. It is also possible to observe that grain growth started at a temperature below 150°C, while holes are visible at 170°C (highlighted with a red circle). The holes were formed in the vicinity of non-preferentially oriented (non-PO) [110] and [100] grains, which were also the site where the hole growth was continuing.

[[File:Picture29.png|400px|center|thumb|Fig. 6: Schematic illustration of the on-axis TKD detector configuration.]]

[[File:Picture30.png|400px|center|thumb|Fig. 6: Schematic illustration of the on-axis TKD detector configuration.]]

 

The yellow rectangles follow instead the delayed hole growth due to the presence of preferentially oriented (PO) [111] grains: the hole is visible from 170°C and grows until it is completely surrounded by larger PO grains, subsequently its growth is retarded until 500°C, while other holes continue to grow. When a hole meets a grain having a low interface energy (in this case a [111] grain), edge retraction is inhibited due to the reduced driving force for dewetting, because these grains are energetically very stable. The low-interface energy grains, which inhibited the retraction, continue to grow at the expense of neighboring grains having higher interface energy, resulting in abnormal grain

growth, and the hole continues to grow in directions where grains along the hole edge have a higher interface energy with the substrate. This expansion only stops when the hole becomes completely sorrounded by low-interface energy grains, as in the case of Fig. 8 and 9.