Ordered phases in ruthenium binary alloys from high-throughput first-principles calculations

Despite the increasing importance of ruthenium in numerous technological applications, e.g., catalysis and electronic devices, experimental and computational data on its binary alloys are sparse. In particular, data are scant on those binary systems believed to be phase-separating. We performed a comprehensive study of ruthenium binary systems with the 28 transition metals, using high-throughput first-principles calculations. These computations predict novel unsuspected compounds in 7 of the 16 binary systems previously believed to be phase-separating and in two of the three systems reported with only a high-temperature $\ensuremath{\sigma}$ phase. They also predict a few unreported compounds in five additional systems and indicate that some reported compounds may actually be unstable at low temperature. These new compounds may be useful in the rational design of new Ru-based catalysts. The following systems are investigated: AgRu${}^{\ensuremath{\star}}$, AuRu${}^{\ensuremath{\star}}$, CdRu${}^{\ensuremath{\star}}$, CoRu${}^{\ensuremath{\star}}$, CrRu${}^{\ensuremath{\star}}$, CuRu${}^{\ensuremath{\star}}$, FeRu${}^{\ensuremath{\star}}$, HfRu, HgRu${}^{\ensuremath{\star}}$, IrRu, MnRu, MoRu, NbRu, NiRu${}^{\ensuremath{\star}}$, OsRu, PdRu${}^{\ensuremath{\star}}$, PtRu, ReRu, RhRu, RuSc, RuTa, RuTc, RuTi, RuV, RuW, RuY, RuZn, and RuZr (a star denotes systems in which the ab initio method predicts that no compounds are stable).