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 SrTiO3 barrier layer was studied. Samples with a structure of glass/NiO(600 angstrom)/Co(100 angstrom)/SrTiO3(400 angstrom)/SrTiO3(20-100 angstrom)/NiFe(100 angstrom) 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-angstrom thick SrTiO3 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. (C) 2003 Elsevier B.V. All rights reserved.