Specific absorption rate of randomly oriented magnetic nanoparticles in a static magnetic field

Numerical simulations using the stochastic Landau-Lifshitz equation are performed to study magnetization dynamics of dilute assemblies of iron oxide nanoparticles exposed to an alternating (ac) magnetic field with an amplitude Hac = 200 Oe and a frequency f = 300 kHz and a static (dc) magnetic field in the range Hdc = 0-800 Oe. The specific absorption rate (SAR) of the assemblies is calculated depending on the angle between the directions of the ac and dc magnetic fields. For the case of an inhomogeneous dc magnetic field created by two opposite magnetic fluxes, the spatial distribution of the SAR in the vicinity of the field-free point is obtained for assemblies with different nanoparticle size distributions. The results obtained seem to be helpful for the development of a promising joint application of magnetic nanoparticle imaging and magnetic hyperthermia.

Automated summary

Numerical simulations were conducted to study the magnetization dynamics of dilute assemblies of iron oxide nanoparticles under alternating and static magnetic fields. The specific absorption rate (SAR) was calculated depending on the angle between the ac and dc magnetic fields. The spatial distribution of SAR near the field-free point was obtained for assemblies with different nanoparticle size distributions, which could be useful for the development of magnetic nanoparticle imaging and magnetic hyperthermia.