In situ study of the ZnO-NaCl system during the growth of ZnO nanorods

Abstract

Synchrotron x-ray diffraction and high temperature SEM examinations were used to study the crystallochemical and morphological evolution of a ZnO-NaCl system during thermal processing. Decomposition of ZnO precursor (Zn-2(OH)(2)CO3 * xH(2)O) at T < 400 degreesC is accompanied by shrinkage and destruction of its fibre-like particles into nanosized isotropic ZnO crystallites. Intensive intergrowth of ZnO nanoparticles and its interaction with coarse NaCl crystallites leads at T = 650-700 degreesC to the formation of a continuous sponge-like framework with an elementary unit size which is far below the initial size of NaCl crystallites. The higher temperature processing at T greater than or equal to 700 degreesC is accompanied by the appearance of nanorods. The role of the metastable liquid phase in the formation of ZnO nanorods at T < 800 degreesC is discussed. Luminescence properties of ZnO nanorods synthesized at 500 and 700 degreesC were demonstrated.