A multipurpose magnetometer for measuring basic magnetic characteristics with a newly designed capacitive torque sensor

An economic and versatile magnetometer for measuring basic magnetic characteristics such as hysteresis loops, magnetic anisotropy and magnetostriction with a single system was built. It is based on the principle that most magnetic characteristics could be obtained by analyzing the torque acting on a sample under an appropriate magnetic field. A capacitive torque sensor with 0.1 nJ resolution measures such torque. By limiting the duration of electromagnetic excitation only to the measuring period (about 4 s), temperature rise of the magnet becomes negligible so that a very compact and economic electromagnet and power supply (10 kg weight, 25 mm air gap, 350 W power consumption, and 480 kA/m of generated field) is realized.