多元醇混合水热法合成MnFe2O4磁性粉体及磁性研究

尺寸小、均匀单分散的MnFe2O4在生物材料、隐身技术、磁流体和锂电池等领域具有巨大的应用潜力.文章采用多元醇混合水热法,以氯化锰(MnCl2·6H2O)、硝酸铁Fe(NO)3·6H2O]作为原料,以氢氧化钠(NaOH)为矿化剂,TERG作为分散剂,制备出了均匀单分散的MnFe2O4纳米磁性粉体.通过改变反应时间,实现了纳米颗粒的尺寸可控制备.采用XRD、TEM和VSM等手段对制备的纳米磁性材料进行表征.实验结果表明,TREG对MnFe2O4纳米颗粒起到了分散作用,随着MnFe2O4纳米磁性颗粒尺寸的减小,其饱和磁化强度、矫顽力均减小,禁带宽度变大,光吸收能力增强,而且当尺寸为5 nm时,出现特征吸收下降现象.

Study on Polyalcohol Mixed Hydrothermal Synthesis of MnFe2O4 Magnetic Powder and Its Magnetic Characteristcs

There are extensive potential applications for small size and uniformly monodispersed MnFe2O4 nanoparticles in the fields of biological materials, stealth technology, magnetic liquid, lithium battery, etc. In this paper, uniformly monodispered MnFe2O4 magnetic nanoparticles were synthesized by using the poloy mixed hydrothermal method, which uses manganese chloride (MnCI2·6H2O) and iron nitrate (Fe(NO)3·6H2O) as the raw material, sodium hydroxide (NaOH) as the mineralizing agent, and TREG as the dispersant. Size controllable synthesis was achieved by controlling the reaction time. The properties of magnetic nanoparticles were tested by X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), etc. Experimental results show that TREG has dispersion effect on MnFe2O4 magnetic nanoparticles and with the decreasing of particle size, its magnetization and coercivity decrease, band gap increases, and light absorption ability enhances. When the particle size is 5nm, unique absorption decline appears.