Influence of barium doping on structural and magnetic properties of bismuth ferrite thin films via spray pyrolysis method

Abstract

Single-phase Bi (1-x) Ba x FeO 3 (0.00 ⩽ x ⩽ 0.20) thin films are successfully deposited on glass substrates by using a spray pyrolysis method. Rietveld analysis of x-ray diffraction patterns confirms that the films are crystallized in a distorted rhombohedral perovskite structure with an R3c space group. No substantial changes in the structure are observed in the samples within the studied doping concentration. The energy dispersive spectroscopy pattern and morphology of the thin films are examined with field emission scanning electron microscopy. Raman modes confirmed slight structural distortions with the increase in Ba concentration. X-ray photoelectron spectroscopy of the thin films shows the effect of Ba 2+ in the formation of Fe 2+ defects and oxygen vacancies. The room temperature magnetic characterizations of the thin films are measured by using a vibrating sample magnetometer within a range of 10 kOe magnetic field. The values of saturation magnetization and the remnant magnetization are increased with an increase in Ba concentration as compared to the pure bismuth ferrite thin film. The optimum value of field-dependent saturation magnetization (2.4069 emu gm −1 ) and field-dependent remnant magnetization (0.6279 emu gm −1 ) are observed for Ba substituted bismuth ferrite samples with x = 0.10.

Synthesis, Characterization, and Photocatalytic Activity of Ba-Doped BiFeO3 Thin Films

“…The present data are not in agreement with the reported data in Ref. [30] that found a decrease in the grain sizes with an increase in Ba due to the oxygen vacancies reduction that appears as an effect of charge compensation mechanism. An increase in grain size has been reported for similar BiFeO 3 system doped with La 3+ [41], NaNbO 3 [42] or even with Ba 3+ [43].…”

“…The XRD pattern for Bi 1−x Ba x FeO 3 thin films (where x = 0, 0.02 and 0.05) measured at room temperature is shown in Figure 2. The XRD peaks for x = 0 and 0.05 corresponding to the planes (010), ( 110 [11,21,26,29,30] with the R3m space group identified with ICDS file no. 01-072-2112.…”

“…Most probably, the Ba-doped BiFeO 3 system is tending to transform from rhombohedral to a pseudo-cubic structure since the value of the tolerance factor for the highest Ba 2+ concentration (x = 0.05) is tilting to 0.9 value. This also results in BFO covalent bonds changes, including bond angles like Fe-O-Fe, Bi-O-Fe, or Bi-O-Bi and bond lengths as Bi-O, Bi-Fe, Bi-Fe that took place due to the internal stresses produced by Ba substitution [30]. To complete the structural discussion, FTIR spectroscopy was employed to study the stretching and bending vibrations of the various bonds present in the studied films.…”

“…By Ba ion substitution on Bi sites, it is also expected that the surface area will increase and improve the photocatalytic activities by decreasing the band gap energy. In the literature Ba-doped BiFeO 3 material as nanoparticles [26], nanofibers [27], ceramics [28], and even as thin films was reported [29,30]. However, there are no reports focused on the Ba-doped BiFeO 3 thin films as photocatalysts.…”

Fabrication, characterization, and antibacterial activity of ferrite, chromite, and aluminate nanoparticles

“…This variation in a values can be related to the ionic radius of Fe 3+ (0.645 Å), Cr 3+ (0.615 Å), and Al 3+ (0.535 Å). Pani et al [13] identified a comparable trend of variation. It is obvious that samples C and A exhibit a lower lattice parameter than that of sample F. According to Bitar et al [48], this variation in the lattice parameter can be attributed to the formation of a secondary phase.…”