Atomic-scale imaging correlation on the deformation and sensing mechanisms of SnO2 nanowires

We demonstrate direct evidence that the strain variation induced by local lattice distortion exists in the surface layers of SnO2 nanowires by coupled scanning transmission electron microscopy and digital image correlation techniques. First-principles calculations suggest that surface reduction and subsurface oxygen vacancies account for such vigorous wavelike strain. Our study revealed that the localized change of surface atomistic configuration was responsible for the observed reduction of elastic modulus and hardness of SnO2 nanowires, as well as the superior sensing properties of SnO2 nanowire network.