title: Size-dependent alternation of magnetoresistive properties in atomic chains.
abstract: Spin-polarized electronic and transport properties of carbon atomic chains are investigated when they are capped with magnetic transition-metal (TM) atoms like Cr or Co. The magnetic ground state of the TM-C(n)-TM chains alternates between the ferromagnetic (F) and antiferromagnetic (AF) spin configurations as a function of n. In view of the nanoscale spintronic device applications the desirable AF state is obtained for only even-n chains with Cr; conversely only odd-n chains with Co have AF ground states. When connected to appropriate metallic electrodes these atomic chains display a strong spin-valve effect. Analysis of structural, electronic, and magnetic properties of these atomic chains, as well as the indirect exchange coupling of the TM atoms through non-magnetic carbon atoms are presented.
authors.affiliation: Department of Physics, Bilkent University, Ankara 06800, Turkey.
authors.forename: E
authors.initials: E
authors.lastname: Durgun
authors.forename: R T
authors.initials: RT
authors.lastname: Senger
authors.forename: H
authors.initials: H
authors.lastname: Mehrez
authors.forename: H
authors.initials: H
authors.lastname: Sevinçli
authors.forename: S
authors.initials: S
authors.lastname: Ciraci