Antisymmetric double exchange in mixed-valence clusters

Abstract Taking into account the spin–orbit interaction in the double exchange (DE) model results in an antisymmetric (AS) DE interaction and anisotropic DE coupling. In the mixed-valence (MV) dimers, the effective AS DE Hamiltonian H ASDE =2i K → ab T ab ( S → b − S → a ) describes the vector type spin-transfer interaction ( K → ab =− K → ba , T ab is the isotropic transfer operator). The AS DE coupling mixes the DE terms and contributes to the cluster ZFS parameters. In the MV trimers, AS DE results in the linear AS DE splittings of the 2S+1 E DE terms, strong magnetic anisotropy and anisotropy of the EPR spectra.