磁性纳米球中的共振涡旋核反转：高效能量吸收与发射的稳健机制

Resonant vortex-core reversal in magnetic nano-spheres as robust mechanism of efficient energy absorption and emission.

作者信息

Kim Sang-Koog, Yoo Myoung-Woo, Lee Jehyun, Lee Jae-Hyeok, Kim Min-Kwan

机构信息

National Creative Research Initiative Center for Spin Dynamics and Spin-Wave Devices, Nanospinics Laboratory, Research Institute of Advanced Materials, Department of Materials Science and Engineering, Seoul National University, Seoul 151-744, South Korea.

出版信息

Sci Rep. 2016 Aug 17;6:31513. doi: 10.1038/srep31513.

DOI:10.1038/srep31513

PMID:27531408

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4987621/

Abstract

We report on novel vortex-core reversal dynamics in nano-spheres of single-vortex spin configuration as revealed by micromagnetic simulations combined with analytical derivations. When the frequency of an AC magnetic field is tuned to the frequency of the vortex-core precession around the direction of a given static field, oscillatory vortex-core reversals occur, and additionally, the frequency is found to change with both the strength of the applied AC field and the particle size. Such resonant vortex-core reversals in nano-spheres may provide a new and efficient means of energy absorption by, and emission from, magnetic nanoparticles, which system can be effectively implemented in bio-applications such as magnetic hyperthermia.

摘要

我们报告了通过微磁模拟与解析推导揭示的单涡旋自旋构型纳米球中新型涡旋核反转动力学。当交流磁场的频率调谐到涡旋核围绕给定静态场方向进动的频率时，会发生振荡涡旋核反转，此外，还发现频率会随所施加交流场的强度和颗粒尺寸而变化。纳米球中的这种共振涡旋核反转可能为磁性纳米颗粒的能量吸收和发射提供一种新的有效手段，该系统可有效地应用于诸如磁热疗等生物应用中。