title: Ferromagnetic order in aged Co-doped TiO2 anatase nanopowders.
abstract: This paper reports on the ferromagnetic properties of aged Ti(1-x)CoxO(2-delta) anatase nanopowders with different Co contents (0.03 < or = x < or = 0.10). It is shown for the first time that aged Co:TiO2 anatase samples retain rather high values of magnetization (M), remanence (Mr) and coercivity (Hc) which provide strong evidence for a preserved long-range ferromagnetic order. Room temperature M, Mr and Hc values were measured in the ranges of [0.05, 0.79] microB/Co, [0.044, 0.096] microB/Co and [366.7,494.8]Oe, respectively, which are in the same range as in general reported either for newly prepared thin films or nanoparticles.
authors.affiliation: Instituto Superior de Engenharia de Lisboa and ICEMS, R. Conselheiro Emídio Navarro 1, 1959-007 Lisboa, Portugal.
authors.forename: A J
authors.initials: AJ
authors.lastname: Silvestre
authors.forename: L C J
authors.initials: LC
authors.lastname: Pereira
authors.forename: M R
authors.initials: MR
authors.lastname: Nunes
authors.forename: O C
authors.initials: OC
authors.lastname: Monteiro