Preparation and Characterization of Bi-Layer-Structured Multiferroic Bi₅Ti₃FeO₁₅ Thin Films Prepared by Pulsed Laser Deposition

Abstract

Bi-layer-structured multiferroic Bi5Ti3FeO15 (BTFO15) thin films have been fabricated on the Pt/TiO2/SiO2/Si substrate at a low temperature of ∼520 °C and various O2 pressures of 0.01–0.12 Torr by pulsed laser deposition, and their dielectric, ferroelectric, and magnetic properties have been characterized. The X-ray diffraction patterns of the BTFO15 thin films indicate the mixed phases of Bi5Ti3FeO15 and pyrochlore Bi2Ti2O7. The BTFO15 thin films (520 °C and 0.12 Torr) show a good ferroelectric hysteresis loop, and a large double remanent polarization (2Pr) of 32 µC/cm2 was obtained at a maximum applied electric field of 1120 kV/cm (40 V) despite the coexistence of the Bi5Ti3FeO15 and pyrochlore Bi2Ti2O7 phases. The magnetic M–H hysteresis measurement shows that a weak ferromagnetic characteristic was also obtained.