A reconstruction of cubic rs-ZnO on MgO (200) substrate through (100) plane of w-ZnO:rs-ZnO for transparent electronic application

ZnO crystallizes in various crystallographic forms. While, the zinc blende (zb) and the rock salt (rs) structure of ZnO occur at high pressure, wurtzite (w) ZnO is the observed structure under ambient conditions. Interestingly, the high pressure polymorph of ZnO, cubic rs-ZnO oxide is presented on MgO (200) substrate at ordinary condition of temperature and pressure. The lattice constant of rs-ZnO is observed to be 4.203 angstrom identical to that for MgO. The possible configurational path for the hexagonal to cubic transformation is proposed. The compression of w-ZnO along c-axis, movement of Zn or O sub-lattice along [(1) over bar 10] direction and (110) plane appears to drive the transition. It has also been observed that rs-ZnO on MgO substrate is stable for certain maximum thickness (150 nm). It may be possible to stabilize the cubic phase at lower temperature and smaller thickness level. (C) 2012 American Institute of Physics. [doi:10.1063/1.3680556]