Influence of antiphase boundary density on the conduction noise properties of epitaxial magnetite thin films

Low frequency conduction noise (1f noise) properties of epitaxial magnetite (Fe3 O4) thin films having a varying density of antiphase boundaries (APBs) were investigated as a function of temperature and frequency. Temperature dependence of noise exhibits a similar behavior to that of resistivity for all the films. The magnitude of normalized noise (Sv V2) decreases with the increasing film thickness, which correlates well with the density of APBs. The quantitative feature of noise, i.e., Hooge parameter has a strong thickness dependence at low temperatures which implies that the APBs play an important role in determining the transport mechanism in epitaxial Fe3 O4 films.