Effect of annealing in the formation of well-crystallized and textured SrFe12O19 films grown by RF magnetron sputtering

Abstract

Abstract We have studied the influence of the annealing treatment on the crystalline growth of SrFe12O19 previously deposited on Si (100) substrates using radio frequency (RF) magnetron sputtering. For this goal, two grown films, with and without ex situ heating step, have been analyzed and compared to determine the differences in their structural, compositional, and magnetic properties. The results obtained by the different analysis techniques, in particular Mössbauer spectroscopy together with EXAFS and XANES data, suggest that the as-grown film is composed of nanocrystalline maghemite nanoparticles and amorphous strontium oxide. Specifically, Mössbauer spectroscopy results pointed out the presence of Fe3+ cations occupying octahedral and tetrahedral sites with hyperfine magnetic fields 49.3 T and 44.2 T, respectively, characteristic of a spinel-related structure. A strontium hexaferrite canonical structure with a c-axis orientation in the sample plane was found for the annealed film. Graphical abstract