An environmental cell transmission electron microscope

Abstract

An aperture-limited, differentially pumped environmental cell has been developed and installed in a JEOL 4000 EX electron microscope. With this environmental cell it is possible to observe, at high spatial resolution, the detailed changes in microstructure that occur during the interaction between a solid and a gaseous environment. The cell has been pressurized to 70 Torr with H2 gas for several hours with no adverse effects on the microscope performance. While the initial tests have been performed with hydrogen gas, the materials used to construct the environmental cell can tolerate corrosive environments. The key features of the environmental cell design along with the results from some applications are presented in this paper.

Hydrogen effects on the interaction between dislocations

“…The in situ deformation experiments were performed in a JEOL 4000 Environmental Cell transmission electron microscope [36,37]. In this instrument, a gas environment can be maintained around the sample, allowing direct observation at a high spatial resolution of the role played by hydrogen during deformation experiments.…”

Hydrogen Embrittlement Understood

“…They conducted deformation experiments inside a transmission electron microscope (TEM) that had been modified to allow the sample volume within the objective pole-piece to be flooded with a gaseous hydrogen environment. [72] Gas pressures up to 20 kPa could be introduced, although dissociation and ionization of the H 2 molecule by the electron beam increased the fugacity by several orders of magnitude. [73] Two types of experiment were conducted.…”

Hydrogen Embrittlement Understood

“…They conducted deformation experiments inside a transmission electron microscope (TEM) that had been modified to allow the sample volume within the objective pole-piece to be flooded with a gaseous hydrogen environment. [72] Gas pressures up to 20 kPa could be introduced, although dissociation and ionization of the H 2 molecule by the electron beam increased the fugacity by several orders of magnitude. [73] Two types of experiment were conducted.…”