SYNTHESIS AND DEHYDRATION OF DOUBLE OXALATES OF RARE EARTHS(III) WITHSOME MONOVALENT METALS .2. INVESTIGATIONS OF RBLN(C2O4)(2)CENTER-DOT-NH(2)O

Double oxalates of rare earths(III) and rubidium with the general form ulae RbCe(C2O4)(2). 4.5H(2)O, RbLn(C2O4)(2).4H(2)O (Ln=Yb, Lu), RbLn(C 2O4)(2).3.5H(2)O (Ln=La, Pr-Dy) and RbLn(C2O4)(2).3H(2)O (Ln=Ho, Er, T m, Y) were synthesized. They were characterized by chemical cal analys is, TG, DTG and DSC over the temperature interval 20-500 degrees C and X-ray powder diffraction examination. At the chosen final temperature (500 degrees C), either oxide (Ln(2)O(3)) or basic carbonate Ln(2)O(2 )CO(3)) and Rb2CO3 were obtained, depending on the rare earth(III) ele ment. On the basis of the X-ray diffraction patterns, the isolated com pounds can be divided into five isostructural groups.