Control of the static and high-frequency magnetic properties of perpendicular anisotropic Co–HfN granular films through insertion of HfN interlayers

Abstract

We propose a multilayer granular structure wherein Hf–nitride (HfN) interlayers are inserted into Co–HfN granular films with perpendicular magnetic anisotropy (PMA) to control their static and high-frequency magnetic properties. The transition between soft ferromagnetic properties and PMA was achieved by varying the thickness of Co–HfN layers (2–30 nm) and HfN interlayers (1–4 nm). The resonance frequency of the Co–HfN (24 nm)/HfN films decreased from 2 to 0.9 GHz with increasing HfN interlayer thickness, owning to the separation of the columnar granules and reduced interlayer interaction between Co–HfN granular layers via a HfN interlayer.

Rotatable magnetic anisotropy in Fe78Si9B13 thin films displaying stripe domains

“…Any in-plane direction being equivalent, the reason why a threshold value for the applied magnetic field must be overcome to induce the stripes rotation along its direction is still not clear, in spite of detailed investigations of the static and dynamic magnetisation processes in this kind of samples [6,12,13,[22][23][24]. Understanding this phenomenon is still an open question that needs to be addressed in order to be able to transfer magnetic thin films having a controlled weak perpendicular anisotropy [25][26][27] into applications, including high-frequency [15,28] or biomedicine [29,30].…”

Magnetic properties and thermal stability of Co/HfN multilayer films for high-frequency application

“…Additionally, while insertion of interlayer was observed to be of great significance for the fabrication of a soft magnetic multilayer structure, relevant studies on the interlayer-controlled transition between PMA and IMA are still limited. 16 In this study, we attempted to control the transition between PMA and IMA by depositing the Co/HfN multilayers with careful variation of thicknesses of the Co layer and HfN interlayer and recorded its high-frequency performance under post-annealing conditions. It is noteworthy that our previous studies have reported growth-induced perpendicular anisotropic Co-HfN nano-granular films.…”