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.