Preparation, crystal structure and electrorheological performance of nano-sized particle materials containing ZrO2

A series of nano-sized particle materials containing ZrO2 was prepared and their compositions were determined by elemental analysis and thermogravimetric analysis (TGA). The effect of particle size and crystal structure type (lattice and space group) on the ER performance of these materials was investigated by X-ray diffraction (XRD) analysis, Raman spectra, the particle size analysis and theological measurement. Their electrorheological (ER) effects show that the ER activities of the ZrO2 materials doped with rare earth (RE = Y, La, Ce, Gd, Tb), whose grain sizes were less than that of pure ZrO2, were lower than that of pure ZrO2, which belongs to the tetragonal crystal system. The ER activity of Y2O3-ZrO2 is the strongest among all the RE-doped ZrO2 materials. The ER activity of the tetragonal phase ZrO2 is higher than that of the monoclinic phase ZrO2. (C) 2003 Elsevier Inc. All rights reserved.