Investigations of Transition Metal Oxide with the Perovskite Structure as Potential Multiferroics; Summary rept. Apr 2006-Apr 2007

摘要

Materials that exhibit both magnetism and ferroelectricity are often termed magnetoelectric multiferroics and are of recent interest because of their potential use in various microelectronic devices. There are many oxides that crystallize in the perovskite structure (ABO3) which are either ferromagnetic or ferroelectric, but relatively few that display both types of properties. This research effort focused on transition metal oxides that crystallize in the perovskite structure as a potential source of multiferroic materials. All materials were prepared as bulk polycrystalline compounds using traditional solid state chemistry techniques. Various concentrations of magnetic atoms (such as Co2+, Fe3+, Cr3+, Mn2+) were substituted into a ferroelectric compound (mainly BaTiO3) in an attempt to induce a magnetic moment in the material without destroying its ferroelectric properties. A solid solution was found to exist between BaTiO3 and LaFeO3, which is an antiferromagnetic oxide with the perovskite structure. Several compounds along this solid solution were also synthesized and characterize in an attempt to locate a novel material that displays the properties of both end members.