Compact Rotating-Sample Magnetometer for Relaxation Phenomenon Measurement Using HTS-SQUID

A compact magnetometer that uses a high-temperature superconductor superconducting quantum interference device (HTS-SQUID) that can measure relaxation phenomena was developed, and its characteristics were evaluated. For measuring magnetic relaxation, a pick-up coil was designed to be fixed at any position in the circle described by a rotating-sample. The pick-up coil was directly connected to an input coil, which is inductively connected to the HTS-SQUID, and the secondary induced magnetic field from the sample was detected with time delay after magnetization. Using the developed system, magnetic signals with time delay from pure water were detected, and the magnetic signal intensity decreased with increasing time delay. This magnetic signal with time delay was not caused by the sample case and the magnetization due to the leaked magnetic field distribution of the permanent magnet used for sample magnetization. Thus, the developed system could detect magnetic signals during the magnetic relaxation process.