Influence of structure and cation distribution on magnetic anisotropy and damping in Zn/Al doped nickel ferrites

An in-depth analysis of Zn/Al-doped nickel ferrites grown by reactive magnetron sputtering is relevant dueto their promising characteristics for applications in spintronics. The material is insulating and ferromagneticat room temperature with an additional low magnetic damping. By studying the complex interplay betweenstrain and cation distribution their impact on the magnetic properties, i.e., anisotropy, damping, andg-factoris unravelled. In particular, a strong influence of the lattice site occupation of Ni2+Tdand cation coordination ofFe2+Ohon the intrinsic damping is found. Furthermore, the critical role of the incorporation of Zn2+and Al3+is evidenced by comparison to a sample of altered composition. Specifically, the dopant Zn2+is evidencedas a tuning factor for Ni2+Tdand therefore unquenched orbital moment directly controlling theg-factor. Astrain-independent reduction of the magnetic anisotropy and damping by adapting the cation distributionis demonstrated