Ferroelectric and magnetic properties in 85 nm-thick Bi6Fe2Ti3O18 thin films by a modified sol-gel processing

• Bi6Fe2Ti3O18 thin films with thickness below 100 nm are first prepared by sol-gel.
• Room temperature Pr is higher than 10 μC/cm2 at 5 V driving voltage.
• Weak ferromagnetism is observed at 5 K.

Bi6Fe2Ti3O18 thin film on Pt/Ti/SiO2/Si substrate with a thickness of 85 nm is successfully prepared by a monoethanolamine-modified sol-gel processing. The prepared thin film is polycrystalline and shows dense morphology. The room temperature remnant polarization is higher than 10 μC cm−2 at 5 V driving voltage both from polarization-voltage hysteresis loop and positive-up negative-down measurements. The polarization after 107 switching cycles and a retention time of 104 s shows no obvious degradation, suggesting good fatigue-resistant characteristics. Weak ferromagnetism is observed at 5 K with a saturated magnetic moment of 11.7 emu/cm3. The results will provide an effective route to optimize Bi6Fe2Ti3O18 thin films with thickness below 100 nm by low-voltage driving.