Structure and Magnetism of Nanocrystalline and Epitaxial (Mn,Zn,Fe)3O4.

摘要

Nanocrystalline (NC) textured Mn0.5Zn0.6Fe1.9O4 (MZFO) films, grown at room temperature on both isostructural and non-isostructural substrates, show magnetization values significantly suppressed from epitaxial MZFO films. X- ray absorption spectroscopy and x-ray magnetic circular dichroism measurements indicate larger ratios of Fe3 to Fe2 ions on the tetrahedral sites in the NC films compared to the epitaxial films. The magnetization loops of the NC films are shifted by 200'400 Oe at low temperatures. No such effect is observed in the epitaxial films. We hypothesize that the presence of a more structurally disordered, possibly magnetically frustrated, matrix exchange biases the crystalline regions.