Dielectric relaxation spectroscopy of montmorillonite doped with 12-tungstophosphoric acid

Aluminum-pillared montmorillonite (PILC MM) was doped with 12-tungstophosphoric acid hexahydrate (WPA-6) by the sol–gel method. Using broad band dielectric relaxation spectroscopy (DRS), electrical properties of the obtained material were investigated. Thermally stimulated depolarization current technique was also used due to its high sensitivity and high resolving power. It has been established that pillared montmorillonite doped with WPA-6 (H3PW12O40 · 6H2O) shows conductivity higher than that of the pure components. Phase transition, which in WPA-6 takes place above 50 °C, in doped montmorillonite occurs above 70 °C. The conductivity activation energy is 0.27 eV.