Synchrotron x-ray study of polycrystalline wurtzite Zn1−xMgxO (⩽x⩽0.15): Evolution of crystal structure and polarization

The effect of Mg substitution on the crystal structure of wurtzite ZnO is presented based on synchrotron x-ray diffraction studies of polycrystalline Zn1−xMgxO (⩽x⩽0.15). Increase in Mg concentration results in pronounced c-axis compression of the hexagonal lattice, and in diminution of the off-center cation displacement within each tetrahedral ZnO4 unit. Going from ZnO to Zn0.85Mg0.15O, significant changes in the ionic polarization are observed (−5.6to−4.8μC∕cm2), despite only subtle increments in the cell volume (∼0.03%) and the ab-area dimension (∼0.1%).