Prediction of lanthanide-containing ternary compounds

Abstract

By substitution of rare-earth (R) elements for La and other group 14 elements (X) for Si in the eight most stable La-Si-P ternary phases obtained previously, the stability of the R-X-P ternary compounds are investigated. We show that the formation energies of many such ternary phases are lowered after the substitution, and some stable ternary phases are obtained under the new convex hulls constructed including the newly predicted low-energy phases. Phonon spectra calculations demonstrate the dynamical stability for these lanthanides containing ternary compounds. The Gibbs formation energies as the function of temperature also demonstrate thermodynamic stability for most of the new phases with respect to the nearby competitive crystal phases in the convex hull. The electronic band structures of these ternary phases show metallic properties and indicate spin polarization for the R₅XP₃ phases. The discoveries of these ternary phases enrich the existing phase diagrams of lanthanide-containing ternary compounds.