Keywords

crystal structures, exhaustive enumeration, alloys, predictions

Abstract

In 2001, S. Müller and A. Zunger [Phys. Rev. Lett. 87, 165502 (2001)] predicted a never-before-observed crystal structure in Ag-Pd. Recently, Curtarolo predicted the same structure to be stable in Pt-Cd and Pt-Pd [S. Curtarolo et. Al., CALPHAD: Comput. Coupling Phase Diagrams Thermochem. 29, 163 (2005)]. The predicted structure is unique in several ways. though never seen in any other face-centered-cubic-based intermetallic binary compound or ordered alloy, it is relatively simple—it contains only four atoms per unit cell. Furthermore, the structure is the only one of this small size, except the L12 structure, that cannot be characterized as a simple stacking of layers where each layer contains only one kind of atom. We construct a first-principles-based Hamiltonian and search it for the thermodynamically stable (lowest energy) structures. Using a (practically) exhaustive enumeration of about three million of the most likely candidate structures, we find that this new structure, designated L13, is indeed a ground state in both Cd-Pt and Pd-Pt. Experimental efforts to validate the predictions are underway.

Original Publication Citation

Gus L. W. Hart, "Verifying predictions of the L13 crystal structure in Cd-Pt and Pd-Pt by exhaustive enumeration," Phys. Rev. B 8 1416 (July 29). The original article may be found here: http://prb.aps.org/abstract/PRB/v8/i1/e1416