Determination of energy barrier distributions of magnetic nanoparticles by temperature dependent magnetorelaxometry
Determination of energy barrier distributions of magnetic nanoparticles by temperature dependent magnetorelaxometry
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DOI：
10.1088/0957-4484/14/12/003
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发表时间：
2003-12-01
期刊：
影响因子：
3.5
通讯作者：
Weber, P
中科院分区：
文献类型：
--
作者：
Romanus, E;Berkov, DV;Weber, P
通过分析磁性纳米粒子的Neel弛豫信号与样品温度的关系，提出了一种表征磁性纳米粒子的新方法。与已有的表征方法不同，新方法直接给出了磁性系统的能垒分布(对于磁流体粒子或其聚集体)。在77~350K温度范围内，对以氧化铁为核、壳层为羧基葡聚糖的磁性纳米颗粒组成的水基磁性流体进行了磁性分级和固定化，定性地研究了分级过程对粒子体系势垒分布的影响。
We present a new method for the characterization of magnetic nanoparticles based on the analysis of the dependence of the Neel relaxation signal on the sample temperature. In contrast to the established characterization methods, the new method directly delivers the energy barrier distribution of the magnetic system (in the case of ferrofluid particles or their aggregates). A water based ferrofluid consisting of magnetic nanoparticles with an iron oxide core and a shell of carboxydextran has been magnetically fractionated and immobilized and the fractions have been investigated in a temperature range from 77 to 350 K. The influence of the fractionation process on the distribution of the energy barriers of the particle system has been studied qualitatively.