Influence of magnetic ordering on electronic, optical and magnetic properties of Bi2Fe4O9

Magnetic properties of nanocrystalline material based on Bi-=SUB=-2-=/SUB=-Fe-=SUB=-4-=/SUB=-O-=SUB=-9-=/SUB=-

“…2. These curves significantly differ from the curves of ceramic and nanocrystalline samples synthesized in various conditions [1,2,7,8]. First of all, it shall be noted that the material shows an unusually high magnetization that substantially exceeds the values specified, for example, in [1,7] (see Table 1).…”

“…Below room temperature, bulk Bi 2 Fe 4 O 9 is an antiferromagnetic with Neel point T N = 237−265 K [7,8].…”

“…Ceramic samples show the presence of impurity phases that may influence the material's magnetic behavior [8][9][10].…”

“…In [8], it was found that Bi 2 Fe 4 O 9 is characterized by collinear ferromagnetic (FM) and noncollinear flat antiferromagnetic (AFM) spin ordering. It was shown that the appearance of non-zero magnetization (about 3 µ B /unit) of Bi 2 Fe 4 O 9 antiferromagnetic may be attributed to the presence of vacancies in the bismuth sublattice.…”

Brief Theoretical Overview of Bi-Fe-O Based Thin Films

“…The typical ferromagnetic perovskite parameters of BFO material stand within a = b = (5.7-6.7) Å [7,8] and hexagonal c = (13-14) Å [5,9]. The angle α is around 60 degrees [10]. The space group orientation is R3c.…”