Abstract
This study aimed to investigate the influence of oxygen flow rate on magnetic and high-frequency properties of as-deposited FeHfO thin films, which were fabricated by DC reactive magnetron sputtering in an Ar + O 2 atmosphere. These films exhibited mixed phases of α-Fe nanograins and amorphous HfO 2 phase, showing nanocrystalline structure and soft magnetic properties. The dispersion character of FeHfO films changed from relaxation-type to resonance-type when the oxygen flow rate varied from 1.0 to 1.2 sccm. Furthermore, the Fe 58.8 Hf 13.1 O 28.1 film with the optimum O 2 flow rate of 1.2 sccm exhibited high saturation magnetization of 10.6 kG, a high resistivity of 258 μΩ cm, a real component of permeability (μ′) of 250 up to 1 GHz and a high ferromagnetic resonance frequency of 2.5 GHz. It is expected that this film should be promising for practical applications as a high-frequency ferromagnetic material. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.