Vapour Phase Growth of Layered MoO3: A New Kinetic Approach for Volatile Metal Oxides

Abstract

AbstractA simple yet versatile growth kinetic method (and device) has been developed in conjunction with present vapour phase preparation of layered MoO3 (orthorhombic). Using purified air at atmospheric pressure a sufficient amount of oxygen is warranted to ensure stoichiometry of grown metal oxide. The empirical vapour condensation rate of MoO3 is RE = 1.20×10-3ΔP2.07 over 642 to 660°C, where ΔP is the partial pressure difference of MoO3 between the source and condensed crystals. Based on observed crystal morphology and XRD result, a more precise MoO3 condensation kinetic model has been developed to explain the layer-by-layer growth of the layered structure. The driving force of the condensation growth is investigated with respect to the experimental set-up. On the basis of this work, it is suggested that the new kinetic approach is suitable for other volatile metal oxides or inorganic crystalline materials when an appropriate preparative atmosphere is selected.