HEATS OF FORMATION OF ALUMINUM-CERIUM INTERMETALLIC COMPOUNDS

The formation heats of the intermetallic compounds of aluminum and cerium were studied using a differential direct isoperibol calorimeter. The composition and equilibrium state of the samples were confirmed by metallographic and X-ray analyses. For the various compounds, the DELTA-H(form) (for the reaction in the solid state at 300 K) was determined as follows (kJ/mol of atoms): Ce3Al: -27.0 +/- 2; CeAl: -46.0 +/- 3; CeAl2: -50.0 +/- 2; and Ce3Al11: -41.0 +/- 2. The results are discussed and compared with the values which can be found in literature.