Accurate measurement of hysteresis curve for Nd-Fe-B sintered magnet with superconducting magnet-based vibrating sample magnetometer

摘要

In recent years, there has been growing interest in the developments of a new measuring system for the hysteresis curve of large voluminal rare-earth magnets. There still remain some problems such as decrease in the maximum field (H_m), the magnetization distortion, and the drift in the hysteresis graph (HG) method, and the eddy current effect in the pulsed-field magnetometer (PF) method [1-3]. Therefore, we made the most use of a superconducting magnet (SCM)-based vibrating sample magnetometer (VSM). We compared the SCM-VSM method with the HG and PF methods to obtain accurate magnetic properties of Nd-Fe-B sintered magnets with very high coercivity (H_(cJ) (≥ 2.1 MA/m).