Particle size and morphology of iridium oxide nanocrystals in non-volatile memory device

The aim of this work is to investigate the particle size and morphology of the nanocrystals in the non-volatile memory device by annular dark field (ADF) scanning transmission electron microscopy (STEM) and conventional transmission electron microscopy (CTEM) techniques. With respect to TEM investigation, statistical analysis on STEM image can acquire the size and density of nanocrystals more accurately than on TEM image. In addition, ADF STEM images successfully provide powerful evidences revealing the structure of IrO., nanocrystals as a core shell structure, where the inner structure is rich in Ir and the outer area is abundant in O or Al. This method could be one of the efficient way for examining the nanocrystals with a complicated cored structure.