...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of magnetism and magnetic materials >Bimodal distribution of the magnetic dipole moment in nanoparticles with a monomodal distribution of the physical size
【24h】

Bimodal distribution of the magnetic dipole moment in nanoparticles with a monomodal distribution of the physical size

机译：具有物理尺寸的单峰分布的纳米粒子中磁偶极矩的双峰分布

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

High-frequency applications of magnetic nanoparticles, such as therapeutic hyperthermia and magnetic particle imaging, are sensitive to nanoparticle size and dipole moment. Usually, it is assumed that magnetic nanoparticles with a log-normal distribution of the physical size also have a log-normal distribution of the magnetic dipole moment. Here, we test this assumption for different types of superparamagnetic iron oxide nanoparticles in the 5-20 nm range, by multimodal fitting of magnetization curves using the MINORIM inversion method. The particles are studied while in dilute colloidal dispersion in a liquid, thereby preventing hysteresis and diminishing the effects of magnetic anisotropy on the interpretation of the magnetization curves. For two different types of well crystallized particles, the magnetic distribution is indeed log-normal, as expected from the physical size distribution. However, two other types of particles, with twinning defects or inhomogeneous oxide phases, are found to have a bimodal magnetic distribution. Our qualitative explanation is that relatively low fields are sufficient to begin aligning the particles in the liquid on the basis of their net dipole moment, whereas higher fields are required to align the smaller domains or less magnetic phases inside the particles.
机译：磁性纳米粒子的高频应用（例如治疗性热疗和磁性粒子成像）对纳米粒子大小和偶极矩敏感。通常，假设具有物理尺寸的对数正态分布的磁性纳米粒子也具有磁偶极矩的对数正态分布。在这里，我们通过使用MINORIM反演方法对磁化曲线进行多峰拟合，测试了5-20 nm范围内不同类型的超顺磁性氧化铁纳米颗粒的这一假设。在稀释的胶体在液体中分散时研究了这些颗粒，从而防止了磁滞现象，并减少了磁各向异性对磁化曲线解释的影响。对于两种不同类型的结晶良好的颗粒，磁分布实际上是对数正态的，这是物理尺寸分布所期望的。然而，发现具有孪晶缺陷或不均匀氧化物相的两种其他类型的颗粒具有双峰磁性分布。我们的定性解释是，相对较低的磁场足以根据其净偶极矩开始将液体中的粒子对准，而需要较高的磁场来对准粒子中的较小畴或较少磁相。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号