  We report on the functionalization of multiferroic BiFeO3 epitaxial films for
spintronics. A first example is provided by the use of ultrathin layers of
BiFeO3 as tunnel barriers in magnetic tunnel junctions with La2/3Sr1/3MnO3 and
Co electrodes. In such structures, a positive tunnel magnetoresistance up to
30% is obtained at low temperature. A second example is the exploitation of the
antiferromagnetic spin structure of a BiFeO3 film to induce a sizeable (~60 Oe)
exchange bias on a ferromagnetic film of CoFeB, at room temperature.
Remarkably, the exchange bias effect is robust upon magnetic field cycling,
with no indications of training.
