Magnetism of NiMn2O4-Fe3O4 spinel interfaces - eScholarship

Magnetism of NiMn 2 O 4 –Fe 3 O 4 spinel interfaces B. B. Nelson-Cheeseman, 1 * R. V. Chopdekar, 1,2 J. S. Bettinger, 1 E. Arenholz, 3 and Y. Suzuki 1 Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA We investigate the magnetic properties of the isostructural spinel-spinel interface of NiMn 2 O 4 (NMO)–Fe 3 O 4 . Although the magnetic transition temperature of the NMO film is preserved, both bulk and interface sensitive measurements demonstrate that the interface exhibits strong interfacial magnetic coupling up to room temperature. While NMO thin films have a ferrimagnetic transition temperature of 60 K, both NiFe 2 O 4 and MnFe 2 O 4 are ferrimagnetic at room temperature. Our experimental results suggest that these magnetic properties arise from a thin interdiffused region of (Fe,Mn,Ni) 3 O 4 at the interface, leading to Mn and Ni magnetic properties similar to those of MnFe 2 O 4 and NiFe 2 O 4 .