| Bismuth ferrite is a kind of multiferroic materials which is simultaneously ferroelectric and antiferromagnetic at a room temperature. Its high ferroelectric C urie temperature and ferromagnetic Neel temperature determines that it has a majority of the practical application of prospects for memory,sensors, and spin electronic devices. However, the weak point of it such as the large leakage conductance, weak ferromagnetism and difficulties for synthesis of single-phase crystals that have hampered its application. Scientists around the world have made much research on it and found that the BFO ferromagnetic can be increased by doping that reduce the leakage conductance as well, but the low-temperature synthesis of single-phase crystals is still a challenging subject. In order to solve this problem, I research the effects of the doping of La, Gd and experimental conditions on the formtion of BFO nano-powders, and I hope to prepare high-quality BFO nano-powder by changing the experimental conditions.As the experimental results show :Bismuth ferrite(Bi Fe O3) crystallites were synthesized at the temperature as low as 120 oC by hydrothermal method. In the synthesis, only when the concentration of KOH was 4M and the solvothermal time was 12 h or more, the well-crystallized pure perovskite single-phase undoped BFO powder could be obtained. The as-prepared Bi Fe O3 powders mainly consisted of square type particles. The as-prepared pure Bi Fe O3 powders showed weak ferromagnetism at room temperature.Well-crystallized pure perovskite bismuth ferrite(Bi Fe O3) powders have been synthesized at the temperature as low as 140 oC by a facile hydrothermal method assisted by ethylene glycol. It was found that the ethylene glycol played a key role in the formation of pure Bi Fe O3 at low-temperature. The Bi Fe O3 powders present a nearly spherical microstructure with an average diameter of approximately 10 μm, and which exhibit superstructures consisting of large amounts of nanoparticles with the average size of 8–20 nm. An obvious ferromagnetic response is observed for the as-prepared pure Bi Fe O3 powders. Moreover, the Bi Fe O3 powders exhibit both enhanced visible- light-driven photocatalytic decomposition of rhodamine B and favorable recycling capability.Well-crystallized pure perovskite bismuth ferrite(Bi Fe O3) powders have been synthesized by a facile hydrothermal route at the temperature as low as 130 oC with the aid of acetone. The as-prepared Bi Fe O3 powders mainly consisted of cubic particles with the size range from 50 to 200 nm, which showed weak ferromagnetism at room temperature. Moreover, the bismuth ferrite Bi Fe O3 exhibit efficient photocatalytic activity under visible light irradiation.The present research describes a simple synthesis route of preparing bismuth ferrite nanopowders through soft chemical route using nitrates of bismuth and iron. Tartaric acid is used as a template material. The particle size of the powder lies between 300 and 500 nm. The result of magnetic test revealed that the magnetic moments of the samples were improved by increasing La, Gd content in the BFOPure Bi2Fe4O9 powders have been synthesized by a fac ile hydrothermal route at the temperature as low as 140 oC through using ethanol- water mixture as solvents. It was found that morphology of Bi2Fe4O9 powders change gradually from cubic to plate with the decrease in the content of ethanol in ethanol-water mixture, the bandwidth decreases, and the specific surface areawere increased. When the ethanol / water ratio was 1:1, the as-prepared pure Bi2Fe4O9 powders showed the minimum bandwidth and the largest specific surface area, which exhibit enhanced visible-light-driven photocatalytic decomposition of rhodamine B. |
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