Room temperature spin filtering in epitaxial cobalt-ferrite tunnel barriers

Abstract

We report direct experimental evidence of room temperature spin filtering in magnetic tunnel junctions (MTJs) containing CoFe2O4 tunnel barriers via tunneling magnetoresistance (TMR) measurements. Pt(111)/CoFe2O4(111)/gamma-Al2O3(111)/Co(0001) fully epitaxial MTJs were grown in order to obtain a high quality system, capable of functioning at room temperature. Spin polarized transport measurements reveal significant TMR values of -18% at 2 K and -3% at 290 K. In addition, the TMR ratio follows a unique bias voltage dependence that has been theoretically predicted to be the signature of spin filtering in MTJs containing magnetic barriers. CoFe2O4 tunnel barriers therefore provide a model system to investigate spin filtering in a wide range of temperatures.

arXiv comment6 pages, 3 figures

References in corpus (5)

• Electronic structure of normal and inverse spinel ferrites from first principles
• Large magnetoresistance using hybrid spin filter devices
• Spin filtering through ferromagnetic BiMnO3 tunnel barriers
• Enhanced magneto-transport at high bias in quasi-magnetic tunnel junctions with EuS spin-filter barriers
• Spin-filter magnetoresistance in magnetic barrier junctions

Cited by in corpus (22)

• Roadmap for Emerging Materials for Spintronic Device Applications
• Effect of epitaxial strain on the cation distribution in spinel ferrites CoFe2O4 and NiFe2O4: a density functional theory study
• Spin-filtering efficiency of ferrimagnetic spinels CoFe2O4 and NiFe2O4
• Magnetic Proximity Effect in Pt/CoFe2O4 Bilayers
• A Robust Approach for the Growth of Epitaxial Spinel Ferrite Films
• Electronic structure and magnetic properties of magnetically dead layers in epitaxial CoFe2O4/Al2O3/Si(111) films studied by X-ray magnetic circular dichroism
• Spinel ferrite nanocrystals embedded inside ZnO: magnetic, electronic and magneto-transport properties
• Growth and characterization of insulating ferromagnetic semiconductor (Al,Fe)Sb
• Engineered spin-valve type magnetoresistance in Fe${}_3$O${}_4$-CoFe${}_2$O${}_4$ core-shell nanoparticles
• Andreev reflection in ferrimagnetic CoFe2O4/SrRuO3 spin filters
• Spin-filter tunnel junction with matched Fermi surfaces
• Interface states in CoFe2O4 spin-filter tunnel junctions
• The role of magnetic anisotropy in spin filter junctions
• Systematic study of the electronic structure and the magnetic properties of a few-nm-thick epitaxial (Ni1-xCox)Fe2O4 (x = 0 - 1) layers grown on Al2O3(111)/Si(111) using soft X-ray magnetic circular dichroism: effects of cation distribution
• Asymmetric Bias Dependence in Double Spin Filter Tunnel Junctions
• Reduced magnetocrystalline anisotropy of CoFe${}_2$O${}_4$ thin films studied by angle-dependent x-ray magnetic circular dichroism
• Spin filtering effect in intrinsic 2D magnetic semiconductor Cr2Ge2Te6
• Effect of tilted magnetic field on magnetosubbands and conductance of bi-layer quantum wire
• Origin of magnetically dead layers in spinel ferrites $M{\text{Fe}}_2{\text{O}}_4$ grown on ${\text{Al}}_2{\text{O}}_3$: Effects of post-deposition annealing studied by XMCD
• Microstructural Effects of Chemical Island Templating in Patterned Matrix-Pillar Oxide Nanocomposites
• Magnetic domain wall pinning in cobalt ferrite microstructures
• Excess current in ferromagnet-superconductor structures with fully polarized triplet component