Spin filtering through ferromagnetic BiMnO3 tunnel barriers

TL;DR

This study demonstrates that ultra-thin ferromagnetic BiMnO3 layers can effectively filter spins during electron tunneling, showing potential for spintronic applications involving complex oxide materials.

Contribution

It provides experimental evidence of spin filtering using ferromagnetic BiMnO3 barriers, highlighting their potential for spin injection in oxide-based spintronic devices.

Findings

50% change in tunnel resistance at 3 K depending on magnetization alignment

Spin filtering efficiency of up to 22% achieved

Potential for using complex ferromagnetic oxides in spintronic applications

Abstract

We report on experiments of spin filtering through ultra-thin single-crystal layers of the insulating and ferromagnetic oxide BiMnO3 (BMO). The spin polarization of the electrons tunneling from a gold electrode through BMO is analyzed with a counter-electrode of the half-metallic oxide La2/3Sr1/3MnO3 (LSMO). At 3 K we find a 50% change of the tunnel resistances according to whether the magnetizations of BMO and LSMO are parallel or opposite. This effect corresponds to a spin filtering effciency of up to 22%. Our results thus show the potential of complex ferromagnetic insulating oxides for spin filtering and injection.