Thermal evaporation and condensation synthesis of metallic Zn layered polyhedral microparticles

Metallic zinc layered polyhedral microparticles have been fabricated by thermal evaporation and condensation technique using zinc as precursor at 750 °C for 120 min and NH₃ as a carrier gas. The zinc polyhedral microparticles with oblate spherical shape are observed to be 2-9 μm in diameter along major axes and 1-7 μm in thickness along minor axes. The structural, compositional and morphological characterizations were performed by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). A vapour-solid (VS) mechanism based growth model has been proposed for the formation of Zn microparticles. Room temperature photoluminescence (PL) emission spectrum of the product exhibited a strong emission band at 369 nm attributed to the radiative recombination of electrons in the s, p conduction band near Fermi surface and the holes in the d bands generated by the optical excitation.