Several wet chemical methods, such as conventional precipitation, microemulsion route and homogeneous precipitation, have been used to prepare nanosized ytterbium oxides. After being calcined at 650 degreesC, well-dispersed spherical particles with size of about 10 nm characterized by TEM observations can be prepared by hydrogen peroxide- or CTAB-aided precipitation process. XRD results show that the as-prepared samples are cubic ytterbium oxides with the crystal sizes of 9.4 nm for hydrogen peroxide-aided way and 6.9 nm for CTAB-containing route. Nitrogen adsorption characterization at 77 K indicates that (i) the present microemulsion process gives a sample with the lowest specific surface area compared with other methods, (ii) ytterbium oxides with specific surface areas of 47.7 m(2)/g (equivalent diameter of 13.6 nm) and 63.2 m(2)/g (equivalent diameter of 10.3 nm) can be prepared by hydrogen peroxide-aided way and CTAB-containing homogeneous precipitation process, respectively. The interaction between the surfactants and the hydrous ytterbia may play an important role in the thermal stability of the derived Yb2O3
