Magnetic Vortices as Efficient Nano Heaters in Magnetic Nanoparticle Hyperthermia
Abstract
Magnetic vortices existing in soft magnetic nanoparticles with sizes larger than the singledomain diameter can be efficient nanoheaters in biomedical applications. Using micromagnetic numerical simulation we prove that in the optimal range of particle diameters the magnetization reversal of the vortices in spherical iron and magnetite nanoparticles is possible for moderate amplitudes of external alternating magnetic field, H_{0} < 100 Oe. In contrast to the case of superparamagnetic nanoparticles, for the vortex configuration the hysteresis loop area increases as a function of frequency. Therefore, high values of the specific absorption rate, on the order of 1000 W/g, can be obtained at frequencies f = 0.51.0 MHz. Because the diameter D of a non singledomain particle is several times larger than the diameter d of a superparamagnetic particle, the volume of heat generation for the vortex turns out to be (D/d)^{3} times larger. This shows the advantage of vortex configurations for heat generation in alternating magnetic field in biomedical applications.
 Publication:

Scientific Reports
 Pub Date:
 January 2018
 DOI:
 10.1038/s41598017181628
 arXiv:
 arXiv:1709.00026
 Bibcode:
 2018NatSR...8.1224U
 Keywords:

 Condensed Matter  Mesoscale and Nanoscale Physics
 EPrint:
 7 pages, 10 figures