Unveiling structural, chemical and magnetic interfacial peculiarities in ?-Fe₂O₃/GaN (0001) epitaxial films.

ABSTRACT: The metastable ?-Fe₂O₃ is known to be the most intriguing ferrimagnetic and multiferroic iron oxide phase exhibiting a bunch of exciting physical properties both below and above room temperature. The present paper unveils the structural and magnetic peculiarities of a few nm thick interface layer discovered in these films by a number of techniques. The polarized neutron reflectometry data suggests that the interface layer resembles GaFeO₃ in composition and density and is magnetically softer than the rest of the ?-Fe₂O₃ film. While the in-depth density variation is in agreement with the transmission electron microscopy measurements, the layer-resolved magnetization profiles are qualitatively consistent with the unusual wasp-waist magnetization curves observed by superconducting quantum interference device magnetometry. Interestingly a noticeable Ga diffusion into the ?-Fe₂O₃ films has been detected by secondary ion mass spectroscopy providing a clue to the mechanisms guiding the nucleation of exotic metastable epsilon ferrite phase on GaN at high growth temperature and influencing the interfacial properties of the studied films.

SUBMITTER: Ukleev V 

PROVIDER: S-EPMC5992217 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature