Magneto-optical spectra of closely spaced magnetite nanoparticles
Magneto-optical spectra of closely spaced magnetite nanoparticles
复制标题
紧密排列的磁铁矿纳米粒子的磁光光谱
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
K. Stokes
中科院分区：
文献类型：
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作者：
Damon A. Smith;Y. Barnakov;B. L. Scott;S. A. White;K. Stokes
发现含有磁铁矿纳米颗粒的复合材料的法拉第旋转光谱取决于组成纳米颗粒的颗粒间间距。该复合材料由化学合成的 Fe3O4（磁铁矿）纳米颗粒（直径 8 nm）和聚甲基丙烯酸甲酯组合而成。制成的复合材料含有一系列纳米颗粒浓度。主要光谱特征的峰值取决于纳米颗粒浓度；观察到该峰从大约 470 nm（稀释复合材料）移动到 540 nm（浓缩）。我们提出了一种基于离散偶极近似的理论，该理论解释了磁铁矿颗粒之间的光学耦合。理论计算和实验数据之间的定性相关性表明，光谱峰位置的移动取决于粒子间距离和几何构型。
The Faraday rotation spectrum of composites containing magnetite nanoparticles is found to be dependent on the interparticle spacing of the constituent nanoparticles. The composite materials are prepared by combining chemically synthesized Fe3O4 (magnetite) nanoparticles (8-nm diameter) and poly(methylmethacrylate). Composites are made containing a range of nanoparticle concentrations. The peak of the main spectral feature depends on nanoparticle concentration; this peak is observed to shift from approximately 470 nm for (dilute composites) to 540 nm (concentrated). We present a theory based on the discrete-dipole approximation which accounts for optical coupling between magnetite particles. Qualitative correlations between theoretical calculations and experimental data suggest that the shifts in spectral peak position depend on both interparticle distance and geometrical configuration.