Internal Temperature Measurements by X-Ray Diffraction on Magnetic Nanoparticles Heated by a High-Frequency Magnetic Field

There is a theoretical and experimental controversy on the possibility for magnetic nanoparticles (MNPs) heated by high-frequency magnetic fields to reach a temperature much larger than the one of their environments. Here, the internal temperature of magnetically heated magnetite MNPs is measured using the temperature dependence of their lattice parameter and compared to the one of their environments, measured from reference nonmagnetic particles. Within the uncertainty of our experimental methods, which is estimated to be below 5 °C, the MNP temperature is the same as the one of their environments.