Exchange coupling of a perpendicular ferromagnet to a half-metallic compensated ferrimagnet via a thin hafnium interlayer

Kiril Borisov; Gwenaël Atcheson; Gavin D'Arcy; Yong-Chang Lau; J. M. D. Coey; Karsten Rode

doi:10.1063/1.5001172

Exchange coupling of a perpendicular ferromagnet to a half-metallic compensated ferrimagnet via a thin hafnium interlayer

Materials Science 2017-10-11 v1

Authors: Kiril Borisov , Gwenaël Atcheson , Gavin D'Arcy , Yong-Chang Lau , J. M. D. Coey , Karsten Rode

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Abstract

A thin Hafnium film is shown to act both as an effective diffusion barrier for manganese at a thickness of 0.7 nm, and as an effective exchange coupling layer in a sandwich structure with perpendicular magnetic anisotropy. The magnetic layers are Co $_{20}$ Fe $_{60}$ B $_{20}$ and the low moment ferrimagnet Mn $_2$ Ru $_x$ Ga (MRG). The coupling changes sign at the compensation temperature of MRG and the exchange energy reaches 0.11 mJm $^{-2}$ for the thinnest Hf interlayers. Ruthenium, the usual metal of choice for coupling ferromagnetic layers in thin film heterostructures, cannot be used with the zero-moment half metal MRG because of Ru interdiffusion. Due to its large coercivity near compensation, the MRG can act as an effective source of exchange pinning.

Keywords

perpendicular ferromagnet half-metallic compensated ferrimagnet hafnium interlayer exchange coupling diffusion barrier MRG exchange pinning

Cite

@article{arxiv.1705.02804,
  title  = {Exchange coupling of a perpendicular ferromagnet to a half-metallic compensated ferrimagnet via a thin hafnium interlayer},
  author = {Kiril Borisov and Gwenaël Atcheson and Gavin D'Arcy and Yong-Chang Lau and J. M. D. Coey and Karsten Rode},
  journal= {arXiv preprint arXiv:1705.02804},
  year   = {2017}
}

Exchange coupling of a perpendicular ferromagnet to a half-metallic compensated ferrimagnet via a thin hafnium interlayer

Abstract

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