Polymorphism of two-dimensional antiferromagnets, AgF2 and CuF2

Abstract

We present theoretical study of relative stability as well as of the magnetic and electronic properties of AgF2 and CuF2, in two related structural forms: orthorhombic (ambient pressure form of AgF2) and monoclinic (ambient pressure form of CuF2), using Density Functional Theory. We show, that at P21/c --> Pbca structural transition is associated with weakening of intra-sheet magnetic superexchange. This finding is consistent with the flattening of 2D layers, smaller charge-transfer energy and stronger admixing of Agd/Cud-Fp states in monoclinic structure, comparing to orthorhombic form. Consequently, monoclinic AgF2 should be targeted in experiment as it should show stronger magnetic coupling than its orthorhombic sibling. The dynamically stable P21/c form of AgF2 could be achieved via two alternative paths: by applied negative strain, or by rapid quenching silver(II) difluoride from temperatures higher than 480 K to low temperatures.

arXiv comment12 pages, 5 figures, 5 tables, and electronic supplement of 15 pages

References in corpus (14)

• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Momentum-Dependent Spin Splitting by Collinear Antiferromagnetic Ordering
• The silver route to cuprate analogs
• Epitaxial engineering of flat silver fluorides cuprate analogs
• Charge Transfer and $dd$ excitations in AgF${}_2$
• High-pressure phase transitions of zinc difluoride up to 55 GPa
• Computational study of antiferromagnetic and mixed-valent diamagnetic phase of AgF2: crystal, electronic and phonon structure and p-T phase diagram
• Theoretical study of ternary silver fluorides AgMF4 (M = Co, Ni, Cu) formation at pressures up to 20 GPa
• Fate of doped carriers in silver fluoride cuprate analogues
• Defect trapping and phase separation in chemically doped bulk AgF2
• Strength of Correlations in a Silver Based Cuprate Analogue
• Charge doping to flat AgF2 monolayers in a chemical capacitor setup
• Unexpected coexisting solid solutions in the quasi-binary Ag(II)F2/Cu(II)F2 phase diagram

Cited by in corpus (4)

• Field-free perpendicular magnetization switching by altermagnet with collinear spin current
• Novel Ternary AgIICoIIIF5 Fluoride: Synthesis, Structure and Magnetic Characteristics
• Controlling Orbital Ordering of Intergrowth Structures with Flat [Ag(II)F2] Layers to Mimic Oxocuprates(II)
• Magnetic interactions as a pivotal determinant in stabilizing a novel AgIIAgIIIF5 polymorph with high spin AgIII