Large magnetic anisotropy in quasi one-dimensional spin-1/2 fluoride antiferromagnets with a d(z2)1 ground state

Hybrid density functional calculations are performed for a variety of systems containing d9 ions (Cu2+, Ag2+), and exhibiting quasi-one-dimensional magnetic properties. In particular we study fluorides containing these ions in a rarely encountered compressed octahedral coordination which forces the unpaired electron in the d(z2) orbital. We predict that such systems should exhibit magnetic anisotropies surpassing that of Sr2CuO3 - one of the best realizations of an one-dimensional system known to date. In particular we predict that the inter-chain coupling in the Ag2+ containing [AgF][BF4] should be nearly five orders of magnitude smaller than the intra-chain interaction. Our results indicate that quasi-one-dimensional spin-1/2 systems containing chains with spin sites in a d(z2)1 local ground state could constitute a versatile model for testing modern theories of quantum many-body physics in the solid state.