Figure 2

TEM images: The bright-field images of the interface between (a) region I and region II and (b) region II and region III, (c,d) the corresponding Fast Fourier Transformation filtered high-resolution TEM image, with the white dashed lines showing the boundary between regions I, II and III, (e,f) the SAED patterns taken from the crystals in region I, (g,h) the SAED patterns taken from the columnar crystals in region II and (i) the SAED pattern taken from region III.