Special CMSM Seminar No.316

Nitrides of magnetic 3𝑑 transition metals M = Fe, Co, and Ni are known to form in a variety of compositions and structures with N at.%varying between 10 - 50%. At 20 at.%N, the phase formed is M₄N in an antiperovskite structure. Here N incorporation modifies the electronic structure of the parent metal through a strong M–N hybridization, which selectively shifts the metal 𝑠−𝑝 bands away from Fermi level and promotes spin-polarized 𝑑-electron dominated transport, resulting in a large spin-polarization ratio (SPR). In this work, we demonstrate that a small doping (≈ 5 at.%) of Pd assists in stabilizing thin films of Co₄N [1,2] and Ni₄N [3] with their lattice parameters reaching to the theoretically predicted values. In case of Fe₄N, Pd doping significantly widens the growth temperature – N concentration regime [3]. Utilizing our approach, epitaxial films of Fe₄N, Co₄N and Ni₄N have been deposited and their structural and magnetic properties will be discussed during the presentation.

[1] Akshaya A.etal., J. Super. Novel Mag. 38, 17 (2025).
[2] Akshaya A. et al., Phys. Rev. Materials 10, 074417 (2026).
[3] Akshaya A, et al., pre-print at: http://dx.doi.org/10.2139/ssrn.6538486

ISOGAMI Shinji
Magnetic Recording Materials Group
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