Breakdown by magnetic field in a La 0.7Sr 0.3MnO 3/MgO/Fe spin valve

Abstract

A La 0.7Sr 0.3MnO 3/MgO/Fe spin valve with inverse tunneling magnetoresistance (TMR) was fabricated on a (100) SrTiO 3 substrate by radio frequency magnetron sputtering. Giant TMR ratios up to 540 were obtained. The breakdown of the spin valve was observed at high magnetic field, which was attributed to the joint action of the invalidation of MgO barrier and the shift of Fermi energy in La 0.7Sr 0.3MnO 3 at high magnetic field. © 2012 American Institute of Physics.