m Temperature Magnetic Barrier Layers in Magnetic Tun Junctions Yuri Suzuki, University of California-Berkeley, DMR 0604277 We have demonstrated that a junction composed of all ferromagnetic layers can exhibit distinct magnetic switching behavior. This junction represents a new class of devices where the magnetic barrier layer can perform magnetic filtering functionaiity. The junction behavior is possible due to the strong coupling at the isostructural interface and virtually no coupling at the non-isostructural interface. . Junction resistance as a function of magnetic field for a La 0.7 Sr 0.3 MnO 3 /NiFe 2 O 4 /Fe 3 O 4 junction exhibits distinct high and low resistance states corresponding to the parallel and anti-parallel magnetization states. Cross-sectional high resolution transmission electron microscopy of La 0.7 Sr 0.3 MnO 3 /NiFe 2 O 4 (3 nm)/Fe 3 O 4 trilayer showing high crystallinity and epitaxy of the La 0.7 Sr 0.3 MnO 3 , NiFe 2 O 4 and Fe 3 O 4 films. The La 0.7 Sr 0.3 MnO 3 ,/NiFe 2 O 4 interface is characterized by defects within the spinel structure, while the NiFe O /Fe O