Negative tunneling magnetoresistance by canted magnetization in MgO/NiO tunnel barriers

Hyunsoo Yang; See-Hun Yang; Dong-Chen Qi; Andrivo Rusydi; Hiroyo Kawai; Mark Saeys; Titus Leo; David J. Smith; Stuart S. P. Parkin

doi:10.1103/PhysRevLett.106.167201

Negative tunneling magnetoresistance by canted magnetization in MgO/NiO tunnel barriers

Materials Science 2015-05-27 v1 Mesoscale and Nanoscale Physics

Authors: Hyunsoo Yang , See-Hun Yang , Dong-Chen Qi , Andrivo Rusydi , Hiroyo Kawai , Mark Saeys , Titus Leo , David J. Smith , Stuart S. P. Parkin

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Abstract

The influence of insertion of an ultra-thin NiO layer between the MgO barrier and ferromagnetic electrode in magnetic tunnel junctions has been investigated by measuring the tunneling magnetoresistance and the X-ray magnetic circular dichroism (XMCD). The magnetoresistance shows a high asymmetry with respect to bias voltage, giving rise to a negative value of -16% at 2.8 K. We attribute this to the formation of non-collinear spin structures in the NiO layer as observed by XMCD. The magnetic moments of the interface Ni atoms tilt from the easy axis due to exchange interaction and the tilting angle decreases with increasing the NiO thickness. The experimental observations are further support by non-collinear spin density functional theory.

Keywords

tunneling magnetoresistance MgO/NiO tunnel barrier non-collinear spin structure X-ray magnetic circular dichroism magnetic tunnel junction Schottky barrier

Cite

@article{arxiv.1103.4664,
  title  = {Negative tunneling magnetoresistance by canted magnetization in MgO/NiO tunnel barriers},
  author = {Hyunsoo Yang and See-Hun Yang and Dong-Chen Qi and Andrivo Rusydi and Hiroyo Kawai and Mark Saeys and Titus Leo and David J. Smith and Stuart S. P. Parkin},
  journal= {arXiv preprint arXiv:1103.4664},
  year   = {2015}
}

Negative tunneling magnetoresistance by canted magnetization in MgO/NiO tunnel barriers

Abstract

Keywords

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