High-spin d7 Co(II) compounds have recently been identified as possible platforms for realising highly anisotropic and bond-dependent couplings featured in quantum-compass models such as the celebrated Kitaev model. In order to evaluate this potential, we consider all symmetry-allowed contributions to the magnetic exchange for ideal edge-sharing bonds. Though a combination of ab-initio and cluster many-body calculations we conclude that bond-dependent couplings are generally suppressed in favor of Heisenberg exchange for real materials. Consequences for several prominent materials including Na2Co2TeO6 and BaCo2(AsO4)2 are discussed.
@article{arxiv.2204.09856,
title = {Magnetic Couplings in Edge-Sharing High-Spin $d^7$ Compounds},
author = {Stephen M. Winter},
journal= {arXiv preprint arXiv:2204.09856},
year = {2023}
}
Comments
15 pages, 10 figures; v3 corrects an error in v2 where "trigonal elongation" and "trigonal compression" were accidentally reversed. The published version has always been correct