On the accuracy of maximum entropy reconstruction of high-resolution Z-contrast STEM images.
The accuracy of maximum entropy reconstruction of Z-contrast STEM images has been evaluated with the effects of experimental variables and noise taken into account by the means of image simulation. As the specimen contains atom species of greatly different atomic numbers, special attention is given to the reliability of the position and composition of lighter atoms that are determined from Z-contrast images in the presence of heavier atoms. When the noise is moderate (SNR >2.5), the position of atom columns can be measured within an accuracy of 0.03 nm. With a higher signal-to-noise ratio (SNR >5) the composition of lighter atoms can be resolved reliably from the Z-contrast images. However, when image noise increases, the relative intensity of lighter atoms may deviate from the actual value in the specimen object function.
Sang
Xiahan
X
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 110016 Shenyang, China.
Du
Kui
K
Zhuo
Mujin
M
Ye
Hengqiang
H