title: Relay-Like Exchange Mechanism through a Spin Radical between TbPc2Molecules and Graphene/Ni(111) Substrates.
abstract: We investigate the electronic and magnetic properties of TbPc2single ion magnets adsorbed on a graphene/Ni(111) substrate, by density functional theory (DFT), ab initio complete active space self-consistent field calculations, and X-ray magnetic circular dichroism (XMCD) experiments. Despite the presence of the graphene decoupling layer, a sizable antiferromagnetic coupling between Tb and Ni is observed in the XMCD experiments. The molecule-surface interaction is rationalized by the DFT analysis and is found to follow a relay-like communication pathway, where the radical spin on the organic Pc ligands mediates the interaction between Tb ion and Ni substrate spins. A model Hamiltonian which explicitly takes into account the presence of the spin radical is then developed, and the different magnetic interactions at play are assessed by first-principle calculations and by comparing the calculated magnetization curves with XMCD data. The relay-like mechanism is at the heart of the process through which the spin information contained in the Tb ion is sensed and exploited in carbon-based molecular spintronics devices.
authors.affiliation: S3, Istituto Nanoscienze, CNR , Via Campi 213/A, Modena 41125, Italy.|Universidade de Sao Paulo (IFSC) , Av. Trabalhador são-carlense, São Carlos 400, Brazil.
authors.forename: Simone
authors.initials: S
authors.lastname: Marocchi
authors.affiliation: S3, Istituto Nanoscienze, CNR , Via Campi 213/A, Modena 41125, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Candini
authors.affiliation: Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen , Lotharstrasse 1, Duisburg D-47048, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Klar
authors.affiliation: School of Chemistry, University of Melbourne , Melbourne, Victoria 3010, Australia.
authors.forename: Willem
authors.initials: W
authors.lastname: Van den Heuvel
authors.affiliation: School of Chemistry, University of Melbourne , Melbourne, Victoria 3010, Australia.
authors.forename: Haibei
authors.initials: H
authors.lastname: Huang
authors.affiliation: S3, Istituto Nanoscienze, CNR , Via Campi 213/A, Modena 41125, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Troiani
authors.affiliation: S3, Istituto Nanoscienze, CNR , Via Campi 213/A, Modena 41125, Italy.
authors.forename: Valdis
authors.initials: V
authors.lastname: Corradini
authors.affiliation: S3, Istituto Nanoscienze, CNR , Via Campi 213/A, Modena 41125, Italy.|Dipartimento di Scienze Fisiche, Matematiche e Informatiche, Universitá di Modena e Reggio Emilia , Via Campi 213/A, Modena 41125, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Biagi
authors.affiliation: S3, Istituto Nanoscienze, CNR , Via Campi 213/A, Modena 41125, Italy.|Dipartimento di Scienze Fisiche, Matematiche e Informatiche, Universitá di Modena e Reggio Emilia , Via Campi 213/A, Modena 41125, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: De Renzi
authors.affiliation: Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT) , Eggenstein-Leopoldshafen D-76344, Germany.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Klyatskaya
authors.affiliation: European Synchrotron Radiation Facility (ESRF) , Avenue des Martyrs 71, Grenoble 38043, France.
authors.forename: Kurt
authors.initials: K
authors.lastname: Kummer
authors.affiliation: European Synchrotron Radiation Facility (ESRF) , Avenue des Martyrs 71, Grenoble 38043, France.
authors.forename: Nicholas B
authors.initials: NB
authors.lastname: Brookes
authors.affiliation: Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT) , Eggenstein-Leopoldshafen D-76344, Germany.|Institut de Physique et Chimie des Materiaux de Strasbourg, UMR 7504 UdS-CNRS , Strasbourg 67034 Cedex 2, France.
authors.forename: Mario
authors.initials: M
authors.lastname: Ruben
authors.affiliation: Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen , Lotharstrasse 1, Duisburg D-47048, Germany.
authors.forename: Heiko
authors.initials: H
authors.lastname: Wende
authors.affiliation: S3, Istituto Nanoscienze, CNR , Via Campi 213/A, Modena 41125, Italy.|Dipartimento di Scienze Fisiche, Matematiche e Informatiche, Universitá di Modena e Reggio Emilia , Via Campi 213/A, Modena 41125, Italy.
authors.forename: Umberto
authors.initials: U
authors.lastname: Del Pennino
authors.affiliation: School of Chemistry, University of Melbourne , Melbourne, Victoria 3010, Australia.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Soncini
authors.affiliation: S3, Istituto Nanoscienze, CNR , Via Campi 213/A, Modena 41125, Italy.|Dipartimento di Scienze Fisiche, Matematiche e Informatiche, Universitá di Modena e Reggio Emilia , Via Campi 213/A, Modena 41125, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Affronte
authors.affiliation: S3, Istituto Nanoscienze, CNR , Via Campi 213/A, Modena 41125, Italy.
authors.forename: Valerio
authors.initials: V
authors.lastname: Bellini
keywords: density functional theory; graphene; metal−organic interface; molecular magnetism; spintronics