Effect of rare earth substitution on electrorheological properties of TIO₂

This paper describes a new class of water-free electrorheological (ER) fluids based on nonaqueous doped TiO₂ with rare earth (RE) in silicone oil. The thermal character and crystal structure of these materials are investigated with DSC, TG and XRD. The doped TiO₂ crystals possess anatase phase and their lattice spacing varies significantly with the content of rare earth. The rheological measurements show that the doped TiO₂ ER fluid exhibits an obviously higher shear stress than that of pure TiO₂ ER fluid under dc electric field. Especially, substitution with 10mol% cerium or 8mol% lanthanum for Ti can obtain a relatively high shear stress. On the basis of dielectric and conduction measurements, we preliminarily discuss the influence of the doping of rare earth on ER effects of TiO₂.