Observation of large low field magnetoresistance in ramp-edge tunneling junctions based on doped manganite ferromagnetic electrodes and a SrTiO(sub 3) insulator

摘要

The authors report the fabrication of ferromagnet-insulator-ferromagnet junction devices using a ramp-edge geometry based on (La(sub 0.7)Sr(sub 0.3))MnO(sub 3) ferromagnetic electrodes and a SrTiO(sub 3) insulator. The multilayer thin films were deposited using pulsed laser deposition and the devices were patterned using photolithography and ion milling. As expected from the spin-dependent tunneling, the junction magnetoresistance depends on the relative orientation of the magnetization in the electrodes. The maximum junction magnetoresistance (JMR) of 30% is observed below 300 Oe at low temperatures (T < 100 K).