We report on the new polycrystalline exchange bias system MnN/CoFe, which shows exchange bias of up to 1800Oe at room temperature with a coercive field around 600Oe. The room temperature values of the interfacial exchange energy and the effective uniaxial anisotropy are estimated to be Jeff=0.41mJ/m2 and Keff=37kJ/m3. The thermal stability was found to be tunable by controlling the nitrogen content of the MnN. The maximum blocking temperature exceeds 325∘C, however the median blocking temperature in the limit of thick MnN is 160∘C. Good oxidation stability through self-passivation was observed, enabling the use of MnN in lithographically defined microstructures. As a proof-of-principle we demonstrate a simple GMR stack exchange biased with MnN, which shows clear separation between parallel and antiparallel magnetic states. These properties come along with a surprisingly simple manufacturing process for the MnN films.
@article{arxiv.1501.05162,
title = {Large exchange bias in polycrystalline MnN/CoFe bilayers at room temperature},
author = {Markus Meinert and Björn Büker and Dominik Graulich and Mareike Dunz},
journal= {arXiv preprint arXiv:1501.05162},
year = {2015}
}