Low voltage control of magnetism in BaFe10.2Sc1.8O19/BaTiO3 bilayer epitaxial thin film at temperatures up to 390 K

Electric field control of magnetism (EFCM) at low voltage (≤5 V) and high temperature (≥353 K) is crucial to micro-integrated magnetoelectric devices. In this work, the BaFe10.2Sc1.8O19 (BFSO)/BaTiO3(BTO) bilayer epitaxial thin films are fabricated. Results show that compared to the single BFSO film, there are significant increases in magnetic susceptibility, multiferroic transition temperature (Tcone), and EFCM in BFSO/BTO bilayer films. The room temperature magnetoelectric coupling coefficient in BFSO (80 nm)/BTO (300 nm) bilayer films (189.6 ns/m) is 14.7 times higher than that in the single layer BFSO film and 345 times larger than single crystalline BiFeO3. A change in magnetization ΔM% about 38% at 20 K and 7.1% at 390 K is obtained in the BFSO (80 nm)/BTO (300 nm) bilayer film. Moreover, repeatable low voltage (≤4 V) EFCM with a high signal-to-noise ratio in the BFSO/BTO bilayer film device is verified at temperatures ranging from 20 K to above 390 K. This high temperature EFCM is mainly contributed by the high Tcone of BFSO and strong piezoelectric/magnetostrictive coupling at the BFSO/BTO interface. The above findings enable the potential usage and integration of BFSO/BTO bilayer films into micro-integrated microwave devices.