CeO\(_x\) Elastic Properties: An In Situ Nanocompression Study in Environmental Transmission Electron Microscopy (ETEM)

The ability to have predictive behavior of nanoparticles during bottom-up fabrication requires a fundamental understanding of their mechanical properties, often differing from their bulk counterparts because of the dramatic difference in grain size and free surfaces. Here, a series of in situ nanocompression experiments is performed on cerium oxide nanocubes in an environmental transmission electron microscope, in which the operating conditions of electron dose and gaseous environment are changed. This leads to either oxidation or reduction of the nanoparticles in situ. Utilizing the same nanoparticle under different oxidative states allows a direct comparison of the mechanical property changes. The elastic properties of CeO \(_x\) ${}_x$ nanocubes, \(1.5< x < 2\) $1.5<x<2$ , are compared to the results from a DFT + U simulation. The trends from the two treatments are in general agreement.