Usage of the synchrotron radiation diffraction for “in situ” kinetics study of the nickel tungstenate solid state synthesis

Investigation of solid state reaction between NiO and WO3 was carried out at the station “Time-resolved diffraction” of the storage ring VEPP-3 SSRC BINP SB RAS. The method of time-resolved diffraction and a fast one-coordinate detector OD-3 were used for data acquisition. Exposition time of one frame was 15–20 s and experiments were continued until one of the phases disappeared or intensity of the NiWO4 peak became stable. Temperatures in the furnace were controlled by a thermocouple and were 580°C, 625°C, 675°C and 725°C. Composition of the initial powder ranged from 0.1 NiO+0.9 WO3 to 0.9 NiO+0.1 WO3 through 0.2 at each temperature point. Kinetics of the NiWO4 peak growth was obtained at different temperatures and energy of activation was calculated.