Relation between the Lattice Energy and Melting Point of some Crystalline Substances. Part IX. Oxides and Chlorides of Lanthanides

The approximate proportionality between the lattice energy, -Uo, and the corres­ponding absolute melting point, Tm. among the members of a set of simple and similar substances, appears to be well-established1,2. The same is also true for the absolute boiling point Tb i.e., -U0/Tb \(\approx\) constant, although this constancy is not very impressive and many substances decompose before reaching the boiling point. The oxides and chlorides of the lanthanide elements, have been examined in the present note. as these are expected to form a closely related sot of similar substance