Atmospheric pressure scanning transmission electron microscopy

Abstract

Scanning transmission electron microscope (STEM) images of gold nanoparticles (2.1 nm average diameter) at atmospheric pressure have been recorded through a 0.36 mm thick mixture of CO, O2 and He. This was accomplished using a reaction cell consisting of two electron-transparent silicon nitride membranes mounted on a specially designed specimen rod. Gas flow occurred through plastic tubing from the outside of the microscope to the specimen region and back. Gold nanoparticles of a full width half maximum diameter of 1.0 nm were visible above the background noise and the achieved resolution was 0.5 nm in accordance with calculations of the beam broadening.