Very low 1/f noise at room temperature in fully epitaxial Fe/MgO/Fe magnetic tunnel junctions

TL;DR

This study demonstrates exceptionally low 1/f noise at room temperature in fully epitaxial Fe/MgO/Fe magnetic tunnel junctions, with potential implications for high-performance spintronic devices.

Contribution

It reports the lowest Hooge factors in fully epitaxial Fe/MgO/Fe MTJs, including effects of bias and interface doping, advancing understanding of noise in magnetic tunnel junctions.

Findings

Record low Hooge factors observed in epitaxial MTJs.

Noise asymmetry depends on bias polarity and magnitude.

Carbon doping influences noise characteristics.

Abstract

We report on room temperature 1/f noise in fully epitaxial Fe(45nm)/MgO(2.6nm)/Fe(10nm) magnetic tunnel junctions (MTJs) with and without carbon doping of the Fe/MgO bottom interface. We have found that the normalized noise (Hooge factor) asymmetry between parallel and antiparallel states may strongly depend on the applied bias and its polarity. Both types of MTJs exhibit record low Hooge factors being at least one order of magnitude smaller than previously reported.