Thermal Stability and Dynamic Magnetic Properties of NiO/Fe Multilayered Thin Films Prepared by Oblique-Angle Sputtering Technique

In this work, the bilayer NiO/Fe thin films compared with single-layer Fe film were deposited on Si (100) substrate using the sputtering technique at deposition angles of 0° and 31.5°. Structure, the static magnetic properties, and the temperature dependence of the dynamic magnetic properties in the range from 300 K to 420 K have been investigated. The results show that the nanocrystalline BCC phase of Fe with the average crystallite size of 11-12 nm and (110) preferred orientation is formed during the deposition process. The resonance frequency is found to rise from 1.03 GHz to 1.13 GHz by employing the NiO sublayer for the typically deposited Fe film. Moreover, the resonance frequency increases for the NiO/Fe films from 1.13 GHz to 1.67 GHz as the deposition angle increases from 0° and 31.5° as a result of the increase in the magnetic anisotropy from 16 Oe to 45 Oe. The permeability values decrease for both as-deposited films with increasing temperature; however, the higher values of the permeability are observed for the film obtained at a deposition angle of 31.5°.