AVS 45th International Symposium
    Magnetic Interfaces and Nanostructures Technical Group Tuesday Sessions
       Session MI-TuA

Invited Paper MI-TuA7
Low-Field Magnetoresistive Properties of Manganite and Chromium Oxide Films

Tuesday, November 3, 1998, 4:00 pm, Room 324/325

Session: Emerging Materials and Hybrid Structures
Presenter: A. Gupta, IBM T.J. Watson Research Center
Correspondent: Click to Email
The magnetotransport properties of the manganites has been the subject of intense research during the past few years. These oxides exhibit orders of magnitude change in resistance when subject to a magnetic field in the Tesla range. Reducing the field scale for magnetotransport has been a major goal of many research groups. We have followed two approaches in reducing the field scale in the manganites: (1) exploiting the spin-dependent scattering at grain boundaries by using polycrystalline and bi-epitaxial films for pinning the magnetic domains; and (2) fabrication of magnetic tunnel junctions, in the form of manganite/insulator/manganite structures, where the tunneling current between the ferromagnetic manganite layers depends sensitively on the relative orientation of their magnetization vectors. Both approaches benefit from the nearly half-metallic nature of the manganites and result in significant low field magnetoresistance (up to 100% ) at low temperatures. Recent magnetoresistance results obtained using another half-metallic system, chromium oxide, will also be presented and the similarities and differences between the two systems will be discussed.