Tuning of magnetic properties and structure of granular FeCoZr–Al2O3 nanocomposites by oxygen incorporation

Effect of oxygen incorporation on the magnetic properties and structure of (FeCoZr)x(Al2O3)1−x (17% < x < 65%) nanocomposites sputtered in pure Ar and mixed Ar + O ambient was investigated using Backscattering spectrometry, SQUID-magnetometry, atomic force microscopy/magnetic force microscopy (AFM/MFM) and Mössbauer spectroscopy. The basic differences in the magnetic state of both series were extracted by comparing their coercivity fields, magnetization, MFM magnetic contrast and discussed with regard to the formation of complex FeCo-oxides.