Magnetoresistanssi ferromagneettis-ferroelektrisissä heterostruktuureissa

The magnetoresistance of ferromagnetic-ferroelectric heterostructures has been studied. In these structures, which consist of a single-crystal BaTiO3 substrate and a thin Co film, a well-defined ferroelectric stripe pattern is imprinted into the magnetic layer via interface strain transfer. As a result, the uniaxial magnetic anisotropy axis in neighboring domains rotates by 90° and the magnetic domain walls are strongly pinned onto the ferroelectric boundaries. At least two magnetoresistance effects can occur in these hybrid structures, namely anisotropic magnetoresistance and domain-wall magnetoresistance. To distinguish between these two contributions, four-point transport measurements were conducted with different electrical current and magnetic field directions. The results reveal a clear anisotropic magnetoresistance effect, but the resistance change due to spin transport through ferromagnetic domain walls is negligible