Large tunneling magnetoresistance of a ramp-edge-type junction with a SrTiO3 barrier

Abstract The tunneling magnetoresistance (TMR) of a ramp-edge-type junction with SrTiO 3 barrier layer was studied. Samples with a structure of glass / NiO (600 A )/ Co (100 A )/ SrTiO 3 (400 A )/ SrTiO 3 (20 – 100 A )/ NiFe (100 A ) were prepared by sputtering and etched through electron cyclotron argon ion milling. Nonlinear I – V characteristics were obtained from a ramp-type tunneling junction, with dominant difference between two external magnetic fields (±100 Oe ) perpendicular to the junction edge line. Given a 40- A thick SrTiO 3 barrier, the TMR was 52.7% at a bias voltage of −50 mV . The bias voltage dependence of TMR in a ramp-type tunneling junction was similar to that of the layered TMR junction.