Computational study of antiferromagnetic and mixed-valent diamagnetic phase of AgF2: crystal, electronic and phonon structure and p-T phase diagram

Abstract

Crystal and electronic structure, lattice dynamics and thermodynamic stability of little known mixed valent diamagnetic AgIAgIIIF4 beta form of AgF2 is thoroughly examined for the first time and compared with well known antiferromagnetic AgIIF2 alpha form within the framework of Density Functional Theory based methods, phonon direct method and quasiharmonic approximation. Computed equations of state, bulk moduli, electronic densities of states, electronic and phonon band structures including analysis of optically active modes and p T phase diagram of the alpha/beta system are presented. This study demonstrates that alpha is thermodynamically preferred over beta at all temperatures and pressures of its existance but simultaneously beta is dynamically stable in much broader pressure range. The beta phase is discussed in broader context of isostructural ternary metal fluorides and isolectronic oxides including NaCuO2, the reference compound for existence of CuIII species in high temperature oxocuprate superconductors.

arXiv comment10 pages, 7 figures, 4 Tables, and supplementary information

References in corpus (4)

• Assessing the Performance of Recent Density Functionals for Bulk Solids
• What is the true charge transfer gap in parent insulating cuprates?
• The silver route to cuprate analogs
• Dramatic enhancement of spin-spin coupling and quenching of magnetic dimensionality in compressed silver difluoride

Cited by in corpus (9)

• Charge Transfer and $dd$ excitations in AgF${}_2$
• Fluorides of silver under large compression
• Fate of doped carriers in silver fluoride cuprate analogues
• Charge ordering mechanism in silver fluoride AgF${}_2$
• Polymorphism of two-dimensional antiferromagnets, AgF2 and CuF2
• A silver(II) route to unconventional superconductivity
• Rearrangement of orbitals in KAgF3 due to Kugel-Khomskii mechanism: a Neutron diffraction and Density Functional Theory study
• Magnetic interactions as a pivotal determinant in stabilizing a novel AgIIAgIIIF5 polymorph with high spin AgIII
• Evaluating covalency using RIXS spectral weights: Silver fluorides vs. cuprates