Abstract
The rare earth carbonates, M-2(CO3)(3) . xH(2)O, of Pr(III), Nd(III), Eu(III), Gd(III), Tb(III), Dy(III), Ho(III), Er(III), Tm(III), and Yb(III) have been synthesized by a novel synthetic method involving the reaction of aqueous solutions of the lanthanide(III) chloride with urea at -90degreesC. A study of the infrared (IR) absorption spectra (400-4000 cm(-1)) of the formed products clearly indicates the absence of bands due to urea and shows the characteristic bands of carbonate ion. A general mechanism describing the formation of lanthanide(III) carbonates, M-2(CO3)(3) xH(2)O, is suggested.