Mechanochemical synthesis of rare earth orthovanadates from R2O3 (R = rare earth elements) and V2O5 powders

Lanthanum oxide (La2O3) and vanadium pentoxide (V2O5) mixture was milled by planetary ball mill to investigate the formation of lanthanum orthovanadate (LaVO4) by mechanochemical reaction. The formation of LaVO4 during milling was monitored by a suite of analytical methods including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and inductivity coupled plasma-atomic emission spectrometry (ICP-AES). The LaVO4 powder prepared by 4h milling consists of particles with size up to several microns and has specific surface area of 9.70m2/g. The mechanochemical method can be applied to the synthesis of other rare earth orthovanadates (RVO4; R=Y, Nd, Sm, Gd, Dy and Er). RVO4 prepared by this method has both zircon-type low pressure phase and scheelite-type high pressure one.