Nano-scale ZnO corrosion product on a biodegradable Zn alloy matrix

ZnO is a major and functional corrosion product of Zn. However, much is unknown about the initial stage of ZnO growing on Zn. In the present work, morphology of nano-scale ZnO corrosion products and their orientation relationship (OR) with respect to Zn matrix have been studied by transmission electron microscopy (TEM). Although lattice parameters of the two phases differ not much, the identified OR is [10-10]ZnO//[10-10]Zn, [1-213]ZnO//[1-21-3]Zn. Based on high-resolution TEM observation, Moire ' fringe analysis and calculation, a small volumetric strain of 0.63% is determined to realize a low energy interfacial structure between the two phases. More generally, the present work provides a method for finding low energy interface quickly under TEM by the criterion of satisfying multiple Delta g//g in reciprocal space. This can be seen directly from overlapped diffraction patterns or Fast Fourier transform pattern.