Quasi-Equilibrium, Multifoil Platelets of Copper- and Titanium-Substituted Bismuth Vanadate, Bi2V0.9(Cu0.1−xTix)O5.5−δ, by Molten Salt Synthesis

Abstract

10% copper-substituted (BiCUVOX/Bi2V0.9Cu0.1O5.5−δ) and 5% copper/titanium double-substituted bismuth vanadate (BiCUTIVOX/Bi2V0.9(Cu0.05Ti0.05)O5.5−δ) platelets were formed by molten salt synthesis (MSS) using a eutectic KCl/NaCl salt mixture. The product was phase-pure within the limits of X-ray diffraction. The size and form of the platelets could be controlled by changing the heating temperature and time. The crystallite growth rate at a synthesis temperature of 650 °C and the activation energy for grain growth were determined for BICUTIVOX, which experienced inhibited growth compared to BICUVOX. Quasi-equilibrium, multifoil shapes consisting of lobes around the perimeter of the platelets were observed and explained in the context of relative two-dimensional nucleation and edge growth rates.

Keywords

• bismuth vanadate
• molten salt synthesis
• platelet morphology
• multifoil shape
• Wulff shape
• Ostwald ripening