Multiparametric Magnetic Particle Spectroscopy of CoFe2O4 Nanoparticles in Viscous Media

The detailed signal generation of the magnetization response of magnetic nanoparticles (MNPs) as a result of externally applied magnetic fields with flux densities of several milliTesla is of high interest for biomedical applications like Magnetic Resonance Imaging (MRI) or Magnetic Particle Imaging (MPI). Although, MNPs are already frequently used as contrast agents or tracer materials, experimental data is rarely compared to model predictions due to distinct deviations. In this contribution, we use a customized Brownian dominated CoFe2O4 particle system to compare experimental Magnetic Particle Spectroscopy (MPS) data with Fokker-Planck simulations considering Brownian relaxation. The influences of viscosity, excitation frequency, field-dependency and size distribution are studied. We show that the effective magnetic moment and cluster sizes can be determined using a sample viscosity series. As introduced, such particle systems can serve as model systems to evaluate mathematical expressions and to study...