title: Graphene as a reversible spin manipulator of molecular magnets.
abstract: One of the primary objectives in molecular nanospintronics is to manipulate the spin states of organic molecules with a d-electron center, by suitable external means. In this Letter, we demonstrate by first principles density functional calculations, as well as second order perturbation theory, that a strain induced change of the spin state, from S=1→S=2, takes place for an iron porphyrin (FeP) molecule deposited at a divacancy site in a graphene lattice. The process is reversible in the sense that the application of tensile or compressive strains in the graphene lattice can stabilize FeP in different spin states, each with a unique saturation moment and easy axis orientation. The effect is brought about by a change in Fe-N bond length in FeP, which influences the molecular level diagram as well as the interaction between the C atoms of the graphene layer and the molecular orbitals of FeP.
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala, Sweden.
authors.forename: Sumanta
authors.initials: S
authors.lastname: Bhandary
authors.forename: Saurabh
authors.initials: S
authors.lastname: Ghosh
authors.forename: Heike
authors.initials: H
authors.lastname: Herper
authors.forename: Heiko
authors.initials: H
authors.lastname: Wende
authors.forename: Olle
authors.initials: O
authors.lastname: Eriksson
authors.forename: Biplab
authors.initials: B
authors.lastname: Sanyal
mesh_terms: D003198:Computer Simulation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006108:Graphite / Q000737:chemistry*; D059346:Magnets; D008956:Models, Chemical; D008958:Models, Molecular; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation*; D012399:Rotation
chemical_list: D006108:Graphite