高等学校化学学报 ›› 2011, Vol. 32 ›› Issue (1): 16.

• 研究论文 • 上一篇    下一篇

稳恒磁场下水热法制备钡铁氧体

徐斌,钟云波,傅小明,任忠鸣   

  1. 上海大学上海市现代冶金与材料制备重点实验室, 上海 200072
  • 收稿日期:2010-06-10 修回日期:2010-09-26 出版日期:2011-01-10 发布日期:2010-12-11
  • 通讯作者: 钟云波 E-mail:yunboz@staff.shu.edu.cn
  • 基金资助:

    上海市科委国际合作项目(批准号: 075207015), 国家自然科学基金(批准号:  51034010)和上海市科委重点基础研究项目(批准号:   08JC1410000)资助.

Hydrothermal Synthesis of Ba\|ferrite  in Steady Magnetic Field

XU Bin, ZHONG Yun-Bo*, FU Xiao-Ming, REN Zhong-Ming   

  1. Shanghai Key Laboratory of Modern Metallurgy and Material Processing, Shanghai University, Shanghai 200072, China
  • Received:2010-06-10 Revised:2010-09-26 Online:2011-01-10 Published:2010-12-11
  • Contact: ZHONG Yun-Bo E-mail:yunboz@staff.shu.edu.cn
  • Supported by:

    上海市科委国际合作项目(批准号: 075207015), 国家自然科学基金(批准号:  51034010)和上海市科委重点基础研究项目(批准号:   08JC1410000)资助.

摘要: 利用XRD、SEM、TEM和VSM等检测手段对不同磁场强度下水热法(反应温度:150℃和180℃)制备钡铁氧体粉末进行分析,实验结果表明:无磁场下,150℃时得到的产物为BaFe2O4颗粒,而180℃时产物为片状BaFe12O19颗粒。施加磁场后,150℃和180℃下水热反应产物都为棒状BaFe12O19。随着磁感应强度的增加,水热反应产物中的棒状BaFe12O19的比例呈增加趋势。当磁感应强度达到10T时,可获得直径约100nm以内长度数十微米的纳米棒状单晶BaFe12O19。不同磁感应强度下获得的水热反应产物粒径细小,并呈现超顺磁性;热力学计算结果表明,磁场的施加,使水热反应的磁吉布斯自由能值(负值)达到数百甚至数千kJ/mol,因而从热力学角度影响了水热反应进行的方向,使水热反应朝生成具有更高磁化率产物方向进行。

关键词: 磁场, 钡铁氧体, 水热法, 磁性能, 磁吉布斯自由能

Abstract: By Using XRD, SEM, TEM, and VSM methods, the shape, micro structure and magnetic property of the barium ferrite powder prepared by hydrothermal synthesized in different magnetic field (reactive temperature: 150℃ and 180℃) were discussed . It was shown that, BaFe2O4 powder can be prepared at the reaction temperature of 150℃ without magnetic field, while at the reactive temperature of 180℃ the powder are composed of BaFe12O19 with sheet shape. While with the magnetic field imposed, all the powder are composed of rod-like BaFe12O19 at the reactive temperature of both 150℃ and 180℃. With the increase of magnetic flux density, the proportion of rod-like BaFe12O19 also increased. When the magnetic flux density reached 10T, single-crystal BaFe12O19 with the diameter of about less than 100nm and length of tens of microns has been obtained. The products obtained by hydrothermal reaction under different magnetic flux are all small size and showed paramagnetic property. Thermodynamic calculation results show that with the application of magnetic field, the magnetic Gibbs free energy of hydrothermal reaction reached hundreds or even thousands of kJ/mol. So it changed the hydrothermal reaction in the thermodynamic aspect, which made the hydrothermal reaction turn to generate the product with higher susceptibility.

Key words: Magnetic field, Hydrothermal reaction, Ba-ferrite, Magnetic properties, Magnetic Gibbs free energy

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