Ferroelectric and magnetic properties of Fe-doped BaTiO3 thin films grown by the pulsed laser deposition

Fe-doped BaTiO₃ thin films were grown on (001) oriented SrTiO₃ substrates using pulsed-laser deposition technique. These films had a single-phase character and good epitaxial relationship with the substrate. Polarization-electric field (P-E) hysteresis revealed a saturated polarization with a remnant polarization (P_r) of 13.5 μC/cm² for 10 mol% Fe-doped BaTiO₃ films. Further increase of composition resulted in the large leakage currents and reduction of polarization. The piezoelectric domain switching in the films was confirmed by local hysteresis using piezoelectric force microscopy measurements. The Fe-doped BaTiO₃ thin films exhibited room temperature ferromagnetism, and the magnetization value increased with increasing Fe concentration. Our results demonstrated that the addition of Fe ≤10 mol% in BaTiO₃ induce the ferromagnetism and the switchable ferroelectric state.