Abstract
Epitaxial magnetic heterostructures of have been fabricated with a varying thicknesses of soft ferrite from 5 to 25 nm. We report a change in the regime of magnetic interaction between the layers from rigid-coupling to exchange-spring behavior, above a critical thickness of the soft magnetic layer. We show that the symmetry and epitaxial matching between the spinel structures of and at the interface stabilize the Verwey transition close to the bulk value even for 5-nm-thick . The large interface exchange-coupling constant estimated from low-temperature data confirmed the good quality of the ferrite-ferrite interface and the major role played by the interface in the magnetization dynamics. The results presented here constitute a model system for understanding the magnetic behavior of interfaces in core/shell nanoparticles and magnetic oxide-based spintronic devices.
- Received 29 March 2016
- Revised 20 June 2016
DOI:https://doi.org/10.1103/PhysRevB.94.054405
©2016 American Physical Society