Sc modified multiferroic BiFeO3 thin films prepared through a sol-gel process

Abstract

Multiferroic thin films with the general formula BiFe1−xScxO3 (x=0.0, 0.1, 0.3, and 0.5mol%) (BFS) were synthesized on Pt∕Ti∕SiO2∕Si substrates through a sol-gel deposition method. From the x-ray diffraction (XRD) analysis, it was observed that the unit cell volume increased upon Sc doping up to 0.3mol%. Impure phase appeared for the BFS (Sc: 0.5mol%) films. Leakage current, ferroelectric, and magnetic properties were also found to improve for Sc doping up to 0.3mol%. Room temperature magnetic coercive field for in-plane orientation of films showed the lowest value for BFS (Sc: 0.3mol%) films, which indicates that BFS (Sc: 0.3mol%) films were more magnetically soft. Room temperature value of the magnetodielectric effect in the presence of magnetic field of 8kOe was found to have maximum of 3.36% for the BFS (Sc: 0.3mol%) films. From the x-ray photoelectron spectroscopy measurements, it was observed that the Fe has mixed valency states of 2+ and 3+. The ratio of Fe2+ and Fe3+ was found to decrease slightly in BFS (Sc: 0.3mol%) films. The improved leakage current and M-H loops support the authors’ observation.

Annealing temperature effect on ferroelectric and magnetic properties in Mn-added polycrystalline BiFeO3 films

“…In our previous study [8], relatively high remanent polarization of 89 μC/cm 2 was obtained at the low temperature of 93 K in polycrystalline BiFeO 3 film annealed at 923 K. The leakage current density of the polycrystalline BiFeO 3 film was reduced on the order of 10 −1 A/cm 2 to 10 −8 A/cm 2 at 150 kV/cm by decreasing the measuring temperature to 93 K. It is expected that the reducing the leakage current density and realize ferroelectric hysteresis loops of a well-saturated shape at room temperature. One way to reduce the leakage current density is to add La or Nb for the A-site or Mn, Cr or Ti for the B-site [9][10][11][12][13][14][15][16][17]. The Mn atom is the leading candidate for reducing the leakage current.…”

Magnetoelectric coupling of [00l]-oriented Pb(Zr0.4Ti0.6)O3–Ni0.8Zn0.2Fe2O4 multilayered thin films

“…Similar results, i.e., pronounced MD effects with their measuring frequency dependence, were also observed in a sol-gel-processed Sc-modified BiFeO 3 film. 15 The observed MD effect ͑magnetocapacitance͒ can be explained in terms of the magnetically induced polarization. The application of a longitudinal bias field ͑⌬H 3 ͒ induces a magnetostriction in the NZFO layer along the direction 3.…”

Simple top-down preparation of magnetic Bi0.9Gd0.1Fe1−xTixO3nanoparticles by ultrasonication of multiferroic bulk material

“…Compared to the bulk ceramics, the coercive fields of the synthesized nanoparticles are much smaller and almost negligible for Bi 0.9 Gd 0.1 Fe 1−x Ti x O 3 (x= 0.20) nanoparticles (Table 1). This actually indicates their soft nature and better suitability for device applications [46].…”