Experimental data on the thermal characteristics ofβ-diketonates of rare earth elements (REE) are discussed. Tris chelates LnL3.nH2O and tetrakis chelates Na[LnL4] (L= differentβ-diketones) are considered. The volatility and thermal stability of theseβ-diketonates depend on several factors, e.g. the hydrate composition and the organic substituents in the ligand. Hydrolysis is possible during the dehydration of light REE tris chelates. Increase volatility and thermal stability are maintained by the introduction of sterically hindered and fluorinated substituents onto the chelate ring of the compl