Improvement of multiferroic properties of the Bi5Ti3FeO15 thin films by Ni doping

Pentabismuth trititanium iron pentadecaoxide (Bi5Ti3FeO15, BTFO), which is a multiferroic four-layer Aurivillius phase compound, has received much attention in recent years. In this work, the BTFO and Bi5Ti3Fe0.5Ni0.5O15 (BTFNO) films grown on Pt (200 nm)/TiO2 (50 nm)/SiO2 (500 nm)/Si substrates by pulsed laser deposition. The microstructure, morphology, ferroelectricity, and ferromagnetism of the films were studied at room temperature. It can be seen from the X-ray diffraction diagrams that BTFO and BTFNO films match well with the perovskite structure without other oxide phases. Scanning electron microscope (SEM) images show that BTFNO films exhibit uniform fine grains and higher density, which is instrumental for the development of ferroelectric properties. Therefore, under the electric field strength of 1116 kV/cm, the remnant polarization of BTFNO films (2P(r) = 23.32 mu C/cm(2)) is larger than that of BTFO thin films at room temperature. Furthermore, compared with BTFO films, the saturation magnetization (2M(s)) of BTFNO films is significantly enhanced. It demonstrated that BTFNO films show not only excellent ferroelectricity but also good ferromagnetism, which provides potential applications in information storage.

Automated summary

In this study, BTFO and BTFNO films were grown on Pt/TiO2/SiO2/Si substrates by pulsed laser deposition, and their microstructure, morphology, ferroelectricity, and ferromagnetism were investigated. The results showed that BTFNO films exhibited better ferroelectricity and ferromagnetism, indicating potential applications in information storage.