Single-domain nanoparticle magnetic power losses calibrated with calorimetric measurements

The purpose of this study was to establish a numerical model for calorimetric measurements of magnetic fluids under an alternating magnetic field (AMF). The modified linear response theory (LRT) and Stoner-Wohlfarth theory were applied to investigate heat dissipation from the ferrofluid. The hysteresis area was calculated once the magnetic field value, applied frequency and number weighted distribution of the nanoparticles were known. Magnetic field distribution was calculated for the setup used for performing calorimetric experiments, and field dependent relaxation times were employed to calculate the specific loss power (SLP) in the sample. Subsequently, the results of numerical investigation were compared with the measurements obtained from calorimetric experiments. The Zeeman energy condition was used to delimit the area where LRT is valid. The numerical model calibrated with the calorimetric measurements allowed for the diffusion coefficient and the parameters involved in power dissipation in a ferrofluid to be determined. These parameters were then used to compute total heat dissipation and temperature distribution within the sample. The numerical model matching the calorimetric measurements of heat dissipation from ferrofluids enhanced the reliability of simulations.

---

Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2018).