Soft-magnetic materials characterized using a superconducting solenoid as magnetic source

Magnetization measurements of soft-magnetic materials can be affected if they are characterized using a superconducting solenoid. Recording hysteresis loops while stepping the magnetic field can cause an apparently inverted hysteresis, if due to the pinned remanent flux in the magnet the field at the sample location exceeds the sample's coercive field. Hysteresis loops recorded while sweeping the field can also be affected by ramping rate. The sweeping-rate dependence is caused by leakage currents resulting from the persistent switch and synchronization issues regarding collection of magnetic moment and field data. The resulting errors can be estimated by measuring paramagnetic dysprosium oxide. (c) 2008 American Institute of Physics.