Magnetic anisotropy modulation of magnetite in $Fe3O4/BaTiO3(100)$ epitaxial structures

Temperature dependent magnetometry and transport measurements on epitaxial $Fe3O4$ films grown on $BaTiO3(100)$ single crystals by molecular beam epitaxy show a series of discontinuities, due to changes in the magnetic anisotropy induced by strain from the different crystal phases of $BaTiO3$⁠. The magnetite film is under tensile strain at room temperature, which is ascribed to the lattice expansion of $BaTiO3$ at the cubic to tetragonal transition, indicating that the magnetite film is relaxed at the growth temperature. From the magnetization versus temperature curves, the variation in the magnetic anisotropy is determined and compared with the magnetoelastic anisotropies. These results demonstrate the possibility of using the piezoelectric response of $BaTiO3$ to modulate the magnetic anisotropy of magnetite films.