Laboratoire Matière et Systèmes Complexes (MSC) UMR 7057 (CNRS) and Université Denis Diderot - Sorbonne Paris Cité, 10 rue Alice Domon et Léonie Duquet, 75013 Paris, France.
Soft Matter. 2017 May 31;13(21):3841-3846. doi: 10.1039/c7sm00147a.
The usage of micro or nanorods is steadily increasing in various applications from fundamental research to industry. Therefore their geometrical, mechanical and eventually magnetic properties need to be well determined. Here, using an optical microscope equipped with magnetic tweezers, we report an experimental procedure to obtain all those information on a single magnetic rod. In particular, we measure magnetic susceptibility χ by analyzing the deformation of a rod subjected to a uniform magnetic field. To do so, we refine a theoretical model which takes into account the variation of χ with the internal field. We prove experimentally that this model yields consistent measurements, at any value of the field strength and the incidence angle. From the combination of the different measurements, we also deduce the number of iron oxide nanoparticles which are embedded within the polymer matrix of the superparamagnetic rods under study.
微纳米棒在从基础研究到工业的各种应用中的使用稳步增加。因此，需要很好地确定它们的几何、机械，最终还有磁性能。在这里，我们使用配备有磁镊的光学显微镜，报告了一种实验程序，以便在单个磁棒上获得所有这些信息。具体来说，我们通过分析在均匀磁场中受到的变形来测量磁化率 χ。为此，我们改进了一个理论模型，该模型考虑了 χ 随内场的变化。我们通过实验证明，该模型在任何场强和入射角下都能产生一致的测量结果。通过组合不同的测量结果，我们还推断出所研究的超顺磁棒聚合物基质中嵌入的氧化铁纳米颗粒的数量。
