Barnakov Yuri A, Yu Minghui H, Rosenzweig Zeev
Advanced Materials Research Institute and the Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148, USA.
Langmuir. 2005 Aug 2;21(16):7524-7. doi: 10.1021/la0508893.
The paper describes the synthesis and characterization of the magnetic properties of magnetite/silica nanocomposites using a modified Stober method. Magnetite nanoparticles averaging 8-10 nm in diameter and stabilized with oleic acid in toluene were used as the magnetic component of the nanocomposites. SQUID magnetic measurements and ferromagnetic resonance spectroscopy measurements were performed at each stage of the synthesis to understand the properties of the formed composites. Changes of blocking temperature in ZFC/FC SQUID curves correlated with corresponding changes of the resonance field in the ferromagnetic spectra of the sample at each stage of formation. The paper concludes that it is possible to manipulate the magnetic properties of silica/magnetite composite materials by controlling their surface properties and silica coating thickness.
本文描述了采用改进的施托伯方法合成磁铁矿/二氧化硅纳米复合材料并对其磁性进行表征的过程。平均直径为8 - 10纳米且在甲苯中用油酸稳定的磁铁矿纳米颗粒被用作纳米复合材料的磁性组分。在合成的每个阶段都进行了超导量子干涉仪（SQUID）磁测量和铁磁共振光谱测量，以了解所形成复合材料的性质。在形成的每个阶段，零场冷却/场冷却（ZFC/FC）SQUID曲线中阻塞温度的变化与样品铁磁共振谱中共振场的相应变化相关。本文得出结论，通过控制二氧化硅/磁铁矿复合材料的表面性质和二氧化硅涂层厚度，可以操控其磁性。
