摘要
We observed the small-size-induced hardening and plasticity of brittle ionic MgO as a result of abnormally triggered dislocation gliding on a non-charge-balanced slip system. The indentation tests of «111» MgO pillars revealed an increased hardness with decreasing pillar size, and the tips of the pillars that were ≤200 nm were plastically deformed. The in situ compression tests of «111» MgO nanopillars in transmission electron microscopy verified aligned dislocation-mediated plasticity on the {111}«110» and {100}«110» systems rather than the charge-balanced {110}«110» slip system.