High-Frequency and High-Field Hysteresis Loop Tracer for Magnetic Nanoparticle Characterization

Existing metrology tools for magnetic nanoparticles cannot generate magnetic fields of the necessary high strength at high frequency to determine particle saturation and coercivity at conditions representative of their use, for example, in composite inductor cores, medical imaging, and hyperthermia treatments for cancer. To address this measurement need, this letter presents the design of a high-field and high-frequency hysteresis loop tracer capable of 0.16 T at 46.4 kHz. Hysteresis loops of commercial and custom iron oxide nanoparticles in varying sizes are measured and compared to typical vibrating sample magnetometer results in demonstration of the insight into nanoparticle behavior enabled by the new capabilities.