Abstract: We calculate a spin-polarized conductance in a nanostructure with a composition of a “high-temperature ferromagnetic insulator-graphene-ferroelectric film,” with special attention paid to control of the electric polarization direction and value in a multiaxial ferroelectric film by a misfit strain. We propose a phenomenological model, taking into account the shift of the Dirac point due to the proximity of the ferromagnetic insulator and using the Landauer formula for the conductance of the graphene channel. We derive analytical expressions, which show that the strain-dependent ferroelectric polarization governs the concentration of two-dimensional charge carriers and Fermi level in graphene in a self-consistent way. The obtained results demonstrate the opportunity to control the spin-polarized conductance of graphene by a misfit strain at room and higher temperatures in the nanostructures CoFe2O4-graphene-PbZr0.4Ti0.6O3 and Y3Fe5O12-graphene-PbZr0.4Ti0.6O3, and thus, open up the possibilities for the application of ferromagnetic-graphene-ferroelectric nanostructures as nonvolatile spin filters and spin valves.
Title: Strain engineering of ferromagnetic-graphene-ferroelectric nanostructures
Authors: Eugene A. Eliseev, Anna N. Morozovska, Maksym V. Strikha
DOI: https://doi.org/10.1103/PhysRevApplied.14.024081 Physical Review Applied (2020) 14, 024081
Preprint deposited in the repository: http://arxiv.org/abs/2004.05338