Effects of different high‐pressure syntheses on the magnetization reversal properties of Bi₂FeMnO₆ ceramics

Abstract

Bi2FeMnO6 ceramics were prepared under atmospheric pressure and a high pressure of 1–6 GPa. The effects of different high‐pressure syntheses on the microstructures were analyzed by X‐ray diffraction and Rietveld refinement, scanning electron microscopy–energy‐dispersive spectroscopy, X‐ray photoelectron spectrometer, and Raman spectroscopy test. The temperature dependence of magnetization was systematically investigated for all samples. There was a transition from rhombohedral R3c structure to orthorhombic phase Pnam with increasing synthetic pressure. The samples synthesized under atmospheric pressure are rhombohedral R3c with antiferromagnetic (AFM) magnetic temperature (M–T curves). The samples synthesized under a high pressure of 5–6 GPa are orthorhombic phase Pnam with the magnetization reversal effect, whereas the lower high‐pressure (1–3 GPa) synthesized samples might be in the transitional area between them. This structural transformation is accompanied by the transformation from normal AFM M–T curves to a typical magnetization reversal effect. The relationship between the lattice distortion and the internal magnetic competition mechanism of the material was discussed. The existence of magnetization reversal in these systems may ascribe to the competition between the single‐ion magnetic anisotropy and the Dzyaloshinsky–Moriya interaction.

Microstructures and physical properties of sol–gel derived Ba2FeMnO6 double perovskite

“…16,17 To search for the novel materials with high T C , multiferroicity at RT as well as high spin polarization for spintronics devices, DP oxides like Sr-based Sr 2 B′B″O 6 (B′B″ = FeMo, FeRe, FeMn, FeW, CrMo, CrRe, CrW, and CrOs) [18][19][20][21][22][23][24][25] and Bi-based Bi 2 B′B″O 6 (B′B″ = NiMn, FeMn, CoMn, CoZn, FeCr, FeNi, FeZn, CrCo, CrNi, and CrZn) oxides have been widely investigated. [26][27][28][29][30] However, studies on the Ba-based DP oxides of Ba 2 B′B″O 6 (B′B″ = FeMn, FeMo, FeRe) are very limited. Recently, Ravi and Senthilkumar reported the synthesis of Ba 2 FeMnO 6 (BFMO) DP oxides by chemical combustion route.…”

“…A wide range of physical properties of DP oxides can be achieved by suitable combinations of the B′ and B″ ions 16,17 . To search for the novel materials with high T C , multiferroicity at RT as well as high spin polarization for spintronics devices, DP oxides like Sr‐based Sr 2 B′B″O 6 (B′B″ = FeMo, FeRe, FeMn, FeW, CrMo, CrRe, CrW, and CrOs) 18–25 and Bi‐based Bi 2 B′B″O 6 (B′B″ = NiMn, FeMn, CoMn, CoZn, FeCr, FeNi, FeZn, CrCo, CrNi, and CrZn) oxides have been widely investigated 26–30 . However, studies on the Ba‐based DP oxides of Ba 2 B′B″O 6 (B′B″ = FeMn, FeMo, FeRe) are very limited.…”