title: On the enhancement of magnetic anisotropy in cobalt clusters via non-magnetic doping.
abstract: We show that the magnetic anisotropy energy (MAE) in cobalt clusters can be significantly enhanced by doping them with group IV elements. Our first-principles electronic structure calculations show that Co4C2 and Co12C4 clusters have MAEs of 25 K and 61 K, respectively. The large MAE is due to controlled mixing between Co d- and C p-states and can be further tuned by replacing C by Si. Larger assemblies of such primitive units are shown to be stable with MAEs exceeding 100 K in units as small as 1.2 nm, in agreement with the recent observation of large coercivity. These results may pave the way for the use of nano-clusters in high density magnetic memory devices for spintronics applications.
authors.affiliation: Department of Physics, Virginia Commonwealth University, Richmond, VA 23284-2000, USA.
authors.forename: M Fhokrul
authors.initials: MF
authors.lastname: Islam
authors.forename: Shiv N
authors.initials: SN
authors.lastname: Khanna
mesh_terms: D002244:Carbon / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D003198:Computer Simulation; D060526:Magnetic Fields; D008956:Models, Chemical; D008958:Models, Molecular; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D003035:Cobalt; D002244:Carbon