Analysis of crystal structure and magnetic properties of strontium substituted bismuth ferrite thin films

Abstract

Thin films of Bi(1−x)Sr x FeO3 (X = 0.00, 0.05, 0.10, 0.20, and 0.30) are synthesized on ultra-cleaned glass substrates by simple spray pyrolysis method at 550 °C. The crystal structures of the thin films are investigated by x-ray diffraction (XRD). The Rietveld refinement data for all the thin films are confirmed a single-phase ABO3 type of rhombohedral structure belonging to the R3c space group. The field emission scanning electron microscopy (FESEM) analysis reveals the size of grains from hexagonal to spherical shape with the addition of Sr doping. The vibrational modes are studied by Raman spectroscopy. The x-ray photoelectron spectroscopy (XPS) analysis unravels the influence of Sr2+ in the creation of Fe2+ defects and oxygen vacancies. The room temperature magnetic measurements of the thin films are carried out within a magnetic field range of ±10 kOe. Magnetic hysteresis loop confirms a significant increase in magnetization in Sr modified bismuth ferrite thin films. The composition i.e. X = 0.20 shows maximum enhancement of magnetic properties with saturation and Remanent magnetization values of 5.99 emu g−1 and 1.77 emu g−1, respectively.

A correlation of lattice distortion with the magnetic properties of calcium doped bismuth ferrite thin films

“…The major interest of this work is to observe the modifications in the magnetic properties of BFO after Ca substitution. In earlier work [20,21], we observe that Ba and Sr substitution affects the cycloidal antiferromagnetic structure of BFO and found that at 10% Ba doping BFO and 20% Sr doped BFO, the saturation magnetization, remanent magnetization and coercive field increases significantly. In order to get improvement in overall magnetic properties, we prepared different constituents of Ca doped BFO thin films.…”

“…Also, the volumic mass density decreases continuously with the addition of Ca amount which is responsible for the smaller atomic mass of Ca 2+ (40.07 amu) than that of Bi 3+ (208.98 amu). The degree of structural distortion can be visualized from the tolerance factor (t) of the prepared samples which is calculated similarly as our previous reports [20,21]. All the prepared samples possess R3c type hexagonal structure [37,38].…”

“…Characteristic peaks i.e. Bi 4f 7/2 (158.2 eV), Bi 4f 5/2 (163.6 eV), Fe 2p 3/2 (709.5 eV), Fe 2p 1/2 (723.2 eV), and O 1s (529 eV) were observed for pure BFO thin film samples [20,21]. The O 1s peak observed at 529 eV in Ca doped thin film which is responsible for the creation of oxygen vacancies in the atom.…”

“…Ca doped BFO in general formula Bi 1−x Ca x FeO 3 (x = 0.00, 0.10, 0.15, 0.20, 0.25, and 0.30) thin-film samples were synthesized on clean glass substrates via simple spray pyrolysis technique as described in our previous report [20,21]. The appropriate amount of bismuth nitrate pentahydrate, ferric nitrate nanohydrate and calcium nitrate tetrahydrate of Himedia chemicals PVT.…”

“…In our previous study, we reported that the structural and magnetic properties of BFO thin films can be improved by alkaline earth metal ions such as Ba 2+ and Sr 2+ [20,21]. In this work, we have chosen another magnetically inactive alkaline earth metals from Group II elements i.e.…”