Structural, morphological and optical investigations of θ-Al2O3 ultrafine powder

Single-phase theta-Al2O3 nanopowder has been synthesized by co-precipitation technique. The synthesized powders were sintered at a temperature ranging from 900 to 1200 degrees C. A stable monoclinic phase is observed for the whole sintering temperature range. The purity, chemical bonds, morphology and optical properties of the powders were investigated by different characterization techniques. X-ray diffraction and Brunauere-Emmette-Teller analysis confirms the existence of ultrafine alumina powders with particle diameter of similar to 5 nm and surface area of 100 m(2)/g. The novel optical results such as band gap of 5.8 eV would reveal the viability of observed phase of alumina in advanced semiconductor applications. (C) 2017 Elsevier B.V. All rights reserved.