Structural and magnetic characterization of Fe3O4/Mn3O4 superlattices

High-quality ferrimagnetic superlattices Fe3O4/Mn3O4 were grown on MeO(0 0 1) substrates by molecular beam epitaxy. The modulation coherency and inter face sharpness are characterized by reflection high-energy electron diffrac tion and X-ray diffraction. Magnetization as a function of the applied fiel d (50 kOe) and temperature (20-300 K) was measured. The magnetic response s hows strong dependence on the modulation wavelength. A combined single magn etic transition temperature is predicted to be similar to 600 K for samples with modulation wavelength < 43 Angstrom. An abrupt decrease of the magnet ization is found below 50 K for some superlattices. This feature may be ind uced by the anisotropic energy related to the tetragonal symmetry of Mn3O4. (C) 2000 Elsevier Science B.V. All rights reserved.