First-principles study of phase stability of Gd-doped EuO and EuS

Abstract

Phase diagrams of isoelectronic Eu${}_{1-x}$Gd${}_x$O and Eu${}_{1-x}$Gd${}_x$S quasi-binary alloy systems are constructed using first-principles calculations combined with the standard cluster expansion approach and Monte-Carlo simulations. The oxide system has a wide miscibility gap on the Gd-rich side but forms ordered compounds on the Eu-rich side, exhibiting a deep asymmetric convex hull in the formation enthalpy diagram. The sulfide system has no stable compounds. The large difference in the formation enthalpies of the oxide and sulfide compounds is due to the contribution of local lattice relaxation, which is sensitive to the anion size. The solubility of Gd in both EuO and EuS is in the range of 10-20% at room temperature and quickly increases at higher temperatures, indicating that highly doped disordered solid solutions can be produced without the precipitation of secondary phases. We also predict that rocksalt GdO can be stabilized under appropriate experimental conditions.

14 pages, 6 figures (some with multiple panels), revtex4 with embedded eps

References in corpus (8)

• Quasiparticle self-consistent $GW$ method; a basis for the independent-particle approximation
• Epitaxial influence on the ferromagnetic semiconducotor EuO
• Combining DFT and Many-Body Methods to Understand Correlated Materials
• First-Principles Theory of Competing Order Types, Phase Separation, and Phonon Scattering in Thermoelectric Pb-Sb-Ag-Te Alloys
• GW method applied to localized 4f electron systems
• Soft x-ray magnetic circular dichroism study on Gd-doped EuO thin films
• Simultaneous ferromagnetic metal-semiconductor transition in electron-doped EuO
• Metal-insulator transition in EuO

Cited by in corpus (1)

• Interface Metallic States between a Topological Insulator and a Ferromagnetic Insulator