title: Local tunnel magnetoresistance of an iron intercalated graphene-based heterostructure.
abstract: The lateral variation of the tunnel magnetoresistance (TMR) of a graphene-based vertical heterostructure is studied by spin-polarized scanning tunneling microscopy (SP-STM) using an Fe-coated probe tip. The well-defined heterostructure is obtained by the intercalation of a magnetic Fe monolayer at the graphene/Ir(1 1 1) interface. Its structure is characterized by a moiré pattern with a high corrugation. In contrast to the Fe / Ir(1 1 1) surface, graphene/Fe / Ir(1 1 1) exhibits ferromagnetic order with an out-of-plane easy magnetization axis. At the nanometer scale, our experiments reveal that the moiré pattern induces a lateral variation of the TMR, which reaches 80%. The measured TMR at valleys of the moiré pattern is higher than at hills. We interpret this modulation in terms of a different hybridization between graphene and Fe at valleys and hills due to a different graphene-Fe distance at these sites, which leads to a different transmission of spin-polarized states.
authors.affiliation: Institute of Applied Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Decker
authors.forename: M
authors.initials: M
authors.lastname: Bazarnik
authors.forename: N
authors.initials: N
authors.lastname: Atodiresei
authors.forename: V
authors.initials: V
authors.lastname: Caciuc
authors.forename: S
authors.initials: S
authors.lastname: Blügel
authors.forename: R
authors.initials: R
authors.lastname: Wiesendanger