Abstract
Metastable α″-Fe16N2 has attracted much interest as a candidate for rare-earth-free hard magnetic materials. We demonstrate that Fe16N2 thin films were grown epitaxially on Cr seed layers with MgO (001) substrates by facing-target sputtering. Good crystallinity with the epitaxial relation MgO (001)[110] ∥ Cr (001)[100] ∥ Fe16N2 (001)[100] was obtained. The chemical order parameter, which quantifies the degree of N ordering in the Fe16N2 (the N-disordered phase is α′-Fe8N martensite), reaches 0.75 for Cr-seeded samples. Cr has a perfect lattice constant match with Fe16N2, and no noticeable strain can be assigned to Fe16N2. The intrinsic saturation magnetization of this non-strained Fe16N2 thin film at room temperature is determined to be 2.31 T by polarized neutron reflectometry and confirmed with vibrating sample magnetometry. Our work provides a platform to directly study the magnetic properties of high purity Fe16N2 films with a high order parameter.
Original language | English (US) |
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Article number | 192402 |
Journal | Applied Physics Letters |
Volume | 112 |
Issue number | 19 |
DOIs | |
State | Published - May 7 2018 |
Bibliographical note
Funding Information:Research at ORNL’s Spallation Neutron Source was sponsored by the Scientific User Facilities Division and by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U. S. Department of Energy. Parts of this work were carried out in the Characterization Facility, University of Minnesota, which receives partial support from NSF through the MRSEC Program.
Funding Information:
Research at ORNL's Spallation Neutron Source was sponsored by the Scientific User Facilities Division and by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U. S. Department of Energy. Parts of this work were carried out in the Characterization Facility, University of Minnesota, which receives partial support from NSF through the MRSEC Program.
Publisher Copyright:
© 2018 Author(s).