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 rheological measurement. Their electrorheological (ER) effects show that the ER activities of the ZrO ₂ 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 ZrO ₂.