磁性纳米粒子的阻断温度的测定：好的，坏的和丑陋的
Determination of the blocking temperature of magnetic nanoparticles: The good, the bad and the ugly
摘要：
在磁化强度对温度（M对T）实验中，磁性纳米颗粒（MNP）组件的阻挡区域是T值的区间，其中当从较低的可达温度加热样品时，系统开始响应于施加的磁场H。该区域的位置取决于所施加的场H、体积V、MNP的磁各向异性常数K和该技术的观察时间，由各向异性能垒确定。在多尺寸样品的一般情况下，可以从ZFC-FC实验估计代表性的阻断温度值$T_B$，作为确定有效各向异性常数的一种方式。在这项工作中，数值求解Stoner-Wolfharth两个层次模型与热搅拌是用来模拟ZFC-FC曲线的单尺寸和多尺寸的样品，并确定最佳的方法获得一个代表性的$T_B$值的多尺寸的样品。结果证实了一种技术的基础上提出的ZFC和FC曲线之间的差异的T导数的Micha等人（好），并证明其与两种替代方法的关系：ZFC最大值（坏）和拐点（丑陋）。然后将导数方法应用于实验数据，获得悬浮在己烷中的聚合$Fe_3O_4$ MNP样品的$T_B$分布，与TEM表征具有良好的一致性。
英文摘要：
In a magnetization vs. temperature (M vs. T) experiment, the blocking region of a magnetic nanoparticle (MNP) assembly is the interval of T values were the system begins to respond to an applied magnetic field H when heating the sample from the lower reachable temperature. The location of this region is determined by the anisotropy energy barrier depending on the applied field H, the volume V, the magnetic anisotropy constant K of the MNPs and the observing time of the technique. In the general case of a polysized sample, a representative blocking temperature value $T_B$ can be estimated from ZFC-FC experiments as a way to determine the effective anisotropy constant. In this work, a numerical solved Stoner-Wolfharth two level model with thermal agitation is used to simulate ZFC-FC curves of monosized and polysized samples and to determine the best method for obtaining a representative $T_B$ value of polysized samples. The results corroborate a technique based on the T derivative of the difference between ZFC and FC curves proposed by Micha et al(the good) and demonstrate its relation with two alternative methods: the ZFC maximum (the bad) and inflection point (the ugly). The derivative method is then applied to experimental data, obtaining the $T_B$ distribution of a polysized $Fe_3O_4$ MNP sample suspended in hexane with an excellent agreement with TEM characterization.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
