Room Temperature Magnetic Barrier Layers in Magnetic Tunnel JunctionsYuri 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 La0.7Sr0.3MnO3/NiFe2O4/Fe3O4 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 La0.7Sr0.3MnO3/NiFe2O4(3 nm)/Fe3O4 trilayer showing high crystallinity and epitaxy of the La0.7Sr0.3MnO3, NiFe2O4 and Fe3O4 films. The La0.7Sr0.3MnO3,/NiFe2O4 interface is characterized by defects within the spinel structure, while the NiFe2O4/Fe3O4 interface cannot be seen, indicating a coherent interface.

Broader Impacts

• High school spring internship program with local Oakland, CA high school in its seventh year– One week program including morning tutorials and

training followed by afternoon hands-on sessions in the lab

– Expanded program to include bioengineering and polymer engineering groups

• Summer High School Apprenticeship Research Program– High school students requested to continue to work in

the lab beyond the formal program dates

• Summer and academic year undergraduate research assistants

• Graduate student participation in a number of outreach programs (e.g., Prison University Project- San Quentin Prison, Techbridge- reaching out to inner city girls, Exploratorium)

Yuri Suzuki, University of California-Berkeley, DMR 0604277

High school interns

High school intern at work on the magnetic force microscope