Synthesis of K0.3WO3 tungsten bronze with gaseous permeation of K3PW12O40 by Sm and electrical properties of K0.3WO3 tungsten bronze

The permeation of the rare earth element Sm to the heteropoly compound K3PW12O40 using the rare earth gas phase-heated diffused permeation method at 550 °C is reported for the first time. The studies of infrared spectroscopy (IR) and X-ray diffraction (XRD) indicate that the Keggin structure of the compound is destroyed. The bond of W–O–W is broken and tungsten bronze K0.3WO3 is produced after permeation. Inductively coupled plasma (ICP) and X-ray photoelectron spectroscopy (XPS) were used to determine the percentage composition of the Sm in a permeated sample. The result shows that there is Sm in a permeated sample and Sm interacts with the other component of the compound. Conductivity of compounds before and after permeation was investigated by four-electrode method. It reveals that the conductivity of the permeated sample is 4.18 × 10−4 S cm−1, which is 1000 times higher than that of the original sample.