Draft version
nm. For details regarding domain size estimation, see supporting information. This method is not very accurate
due to the assumptions used to derive the equation. It is also possible that microstrain in the gold domains
could influence the peak broadening. However, the estimation here serves as a comparison between the two
very similar films.41 The results indicate that from 30 to 50 % the Au domains within the MnOx films grow
approximately 150 %.
Figure 1. a) X-ray Diffraction for pure MnOx film, in purple, together with references for Mn3O4 (blue), Mn2O3 (red) and MnO2 (black).
The peaks matching Mn3O4 lines are indicated with blue #. b) X-ray Diffraction results for Au-MnOx films, 50% Au in green and 25 % Au
in teal. A gold reference is shown in orange. The four main peaks for Au is indicated with orange #.
The characterization of surface morphology was performed with Scanning Electron Microscopy. From figure 1ac
it is evident that the surface of MnOx change with increasing gold content. The pure MnOx consists of pyramid
shaped features, whereas the mixed films exhibit roundish features. These images also indicate that the films
with Au have a slightly more open structure which could lead to a higher surface area.
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