Heats of formation of gadolinium—bismuth alloys

Abstract

The heats of formation of Gd—Bi alloys were measured using a direct isoperibol calorimeter. The composition and equilibrium state of the samples were checked by metallographic and X-ray analyses. The following values were found for the different compounds [Δ H form, reaction in the solid state, 300 K, kcal (g-atom) −1 ± 0.5]: Gd 5+ x Bi 3, −20.0 ± 0.7; Gd 5Bi 3, −20.9; Gd 4Bi 3, −22.0; GdBi, −23.1. The results obtained were compared with those already achieved for other rare earth bismuthides.