A Magnetometer for Dynamic Full M–H Loop Measurements in the Megahertz Range

We have developed a dynamicM–Hmeasurement system for high-frequency characterization of magnetic materials. The system employs a solenoid-type excitation coil driven at 1.2 MHz, which can generate magnetic fields up to 0.5 T at its center, enabling full hysteresis measurements of most soft magnetic materials. The phase delay between the excitation current and pickup voltage signals is calibrated using a paramagnetic Dy2O3powder, and both the magnetic moment and applied fields of the system are calibrated with a sphere of YIG single crystal as a standard. We measured Ni–Zn ferrite and confirmed that our system can reliably capture complete dynamic magnetization loops at megahertz frequencies, providing a powerful tool for both fundamental research and practical evaluation of soft magnetic materials.