Fe/MgO/Fe (100) textured tunnel junctions exhibiting spin polarization features of single crystal junctions

TL;DR

This study shows that textured Fe/MgO/Fe magnetic tunnel junctions exhibit spin polarization features similar to single crystal junctions, due to their structural coherence and magnetic quality at the nanoscale.

Contribution

It demonstrates that textured junctions can replicate single crystal spin transport features by maintaining nanoscale structural coherence.

Findings

Transport properties are similar in textured and epitaxial junctions.

Structural coherence at the nanoscale is sufficient for spin polarization signatures.

Textured junctions can be modeled as parallel nanometer-sized single crystal junctions.

Abstract

Crystallographic and spin polarized transport properties of (100) textured and (100) epitaxial Fe/MgO/Fe magnetic tunnel junctions are compared. Strong similarities in the transport properties show that structural coherence and magnetic quality at the 25 nm grain scale in textured junctions are sufficient to issue signatures of the spin polarized transport specific to a single crystal junction. This demonstrates that the lateral coherence of the Bloch tunneling wave function is identically limited in both systems. Our analysis leads to model the textured tunnel junction as a juxtaposition of nanometer sized single crystal junctions, placed in parallel.