Abstract
We report the discovery of an antiferromagnetic coupling of the magnetic moment of chromium(II) tetraphenyl-porphyrin (CrTPP) molecules to the magnetization of the clean ferromagnetic Co(001) substrate. We assign this unusual molecule-substrate exchange coupling to the less than half-filled chromium orbitals interacting with Co valence band electrons via porphyrin-ligand molecular orbitals. X-ray magnetic circular dichroism, x-ray photoelectron spectroscopy, and scanning tunneling microscopy are combined with calculations and provide evidence for a surprising type of antiferromagnetic indirect magnetic exchange coupling.
- Received 19 March 2014
- Revised 10 November 2014
DOI:https://doi.org/10.1103/PhysRevB.90.220404
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