WHAT ARE THE OPTIMAL CONDITIONS FOR DETECTION OF A SMALL PORE BY HIGH RESOLUTION TRANSMISSION ELECTRON MICROSCOPY?

High resolution transmission electron microscopy (HRTEM) gives us the possibility to observe nanometric features in a sample such as dislocations, precipitates, nano-particles, nucleation of nano-crystals and small pores mainly due to the phase contrast. If such features are too small (much smaller than the sample thickness) we may not be able to detect them, which means we will see no difference with or without the feature.

In this work we use HRTEM simulations to estimate the optimal conditions that allows to detect a small pore in TEM. We used EMS software to simulate HRTEM images of a cubic-yttrium stabilized zirconia (YSZ) TEM specimen with a thickness of 12nm and a fine surface roughness (a few Ångstroms). MATLAB was used to create an artificial pore in the YSZ bulk by removing a cluster of atoms. Various pore sizes were analyzed (diameter of 8-30Å). By creating a defocus series in EMS the optimal microscope conditions for detection of small pores were evaluated.