This review provides a guide to the recent literature on the character
ization of the decomposition routes of different precursors, especiall
y carboxylates of rare earth metals (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, D
y, Ho, Er, Tm, Yb, Lu, Y and Th), and the formation of the final oxide
products. it also discusses the effects of (1) the nature of precurso
rs, i.e. acetate, oxalate, carbonates, etc., (2) the nature and stabil
ity of the intermediates formed during decomposition, (3) the calcinat
ion temperature and (4) the composition of the gas atmosphere, i.e. N-
2, H-2, O-2, air and vacuum, on the chemical composition, structure, t
exture and catalytic activity of the generated oxides.