Serantes David, Baldomir Daniel
Instituto de Investigacións Tecnolóxicas and Applied Physics Department, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Nanomaterials (Basel). 2021 Oct 21;11(11):2786. doi: 10.3390/nano11112786.
The likelihood of magnetic nanoparticles to agglomerate is usually estimated through the ratio between magnetic dipole-dipole and thermal energies, thus neglecting the fact that, depending on the magnitude of the magnetic anisotropy constant (), the particle moment may fluctuate internally and thus undermine the agglomeration process. Based on the comparison between the involved timescales, we study in this work how the threshold size for magnetic agglomeration (daggl) varies depending on the value. Our results suggest that small variations in -due to, e.g., shape contribution, might shift daggl by a few nm. A comparison with the usual estimation is provided, as well as with the energy competition approach. In addition, based on the key role of the anisotropy in the hyperthermia performance, we also analyse the associated heating capability, as non-agglomerated particles would be of high interest for the application.
磁性纳米颗粒发生团聚的可能性通常是通过磁偶极-偶极相互作用能与热能之间的比值来估算的，因此忽略了这样一个事实：取决于磁各向异性常数（）的大小，粒子磁矩可能会在内部发生波动，从而破坏团聚过程。基于相关时间尺度之间的比较，我们在这项工作中研究了磁性团聚的阈值尺寸（daggl）如何随值而变化。我们的结果表明，例如由于形状贡献导致的值的微小变化可能会使daggl偏移几纳米。我们将其与通常的估计方法以及能量竞争方法进行了比较。此外，基于各向异性在热疗性能中的关键作用，我们还分析了相关的加热能力，因为未团聚的颗粒对于该应用具有很高的价值。
