Atomic-Scale Imaging of Cation Ordering in Inverse Spinel Zn2SnO4 Nanowires

By using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) coupled with density functional theory (DFT) calculations, we demonstrate the atomic-level imaging of cation ordering in inverse spinel Zn2SnO4 nanowires. This cation ordering was identified as 1:1 ordering of Zn2+ and Sn4+ at the octahedral sites of the inverse spinel crystal with microscopic symmetry transition from original cubic Fd3̅m to orthorhombic Imma group. This ordering generated a 67.8% increase in the elastic modulus and 1–2 order of magnitude lower in the electric conductivity and electron mobility compared to their bulk counterpart.