Ionically-Driven Synthesis and Exchange Bias in Mn$_{4}$N/MnN$_{x}$ Heterostructures

Zhijie Chen; Christopher J. Jensen; Chen Liu; Xixiang Zhang; Kai Liu

doi:10.1063/5.0165895

paper

Ionically-Driven Synthesis and Exchange Bias in Mn $_{4}$ N/MnN $_{x}$ Heterostructures

arXiv:2308.04274 · doi:10.1063/5.0165895

Abstract

Ferrimagnets have received renewed attention as a promising platform for spintronic applications. Of particular interest is the Mn4N from the $ε$ -phase of the manganese nitride as an emergent rare-earth-free spintronic material due to its perpendicular magnetic anisotropy, small saturation magnetization, high thermal stability, and large domain wall velocity. We have achieved high-quality (001)-ordered Mn $_{4}$ N thin film by sputtering Mn onto $η$ -phase Mn $_{3}$ N $_{2}$ seed layers on Si substrates. As the deposited Mn thickness varies, nitrogen ion migration across the Mn $_{3}$ N $_{2}$ /Mn layers leads to a continuous evolution of the layers to Mn $_{3}$ N $_{2}$ /Mn $_{2}$ N/Mn $_{4}$ N, Mn $_{2}$ N/Mn $_{4}$ N, and eventually Mn $_{4}$ N alone. The ferrimagnetic Mn $_{4}$ N indeed exhibits perpendicular magnetic anisotropy, and forms via a nucleation-and-growth mechanism. The nitrogen ion migration is also manifested in a significant exchange bias, up to 0.3 T at 5 K, due to the interactions between ferrimagnetic Mn $_{4}$ N and antiferromagnetic Mn $_{3}$ N $_{2}$ and Mn $_{2}$ N. These results demonstrate a promising all-nitride magneto-ionic platform with remarkable tunability for device applications.

21 pages, 5 figures, 7 pages of supplementary material with 5 figures

Ionically-Driven Synthesis and Exchange Bias in Mn4​N/MnNx​ Heterostructures

Abstract

References in corpus (8)

Ionically-Driven Synthesis and Exchange Bias in Mn $_{4}$ N/MnN $_{x}$ Heterostructures