KAgF3: Quasi-one-dimensional magnetism in three-dimensional magnetic ion sublattice

The electronic structure and magnetic properties of the Jahn–Teller-distorted perovskite KAgF3 have been investigated using the full-potential linearized augmented plane-wave method. It is found that KAgF3 exhibits significant quasi-one-dimensional antiferromagnetism with the ratio of exchange constant |J⊥||J⊥| (perpendicular to the z-axis) and J (along the z-axis) about 0.04, although the sublattice of magnetic ion is three-dimensional. The strong quasi-one-dimensional antiferromagnetism originates from the C  -antiferro-distortive orbital ordering of the Ag2+4d9 ions. The orbital ordered antiferromagnetic insulating state in KAgF3 is determined by on-site Coulomb repulsion to a large extent.

► We have demonstrated that late 4d compound KAgF3 exhibits a quasi-one-dimensional antiferromagnetism. ► It originates from the C  -antiferro-distortive hole-orbital ordering of the Ag2+4d9Ag2+4d9 ions. ► The strong-correlated effect is very important in determining the orbital ordering in KAgF3.