Compensating vibrating reed magnetometer (invited)

A new high-sensitivity magnetometer for susceptibility measurements in the temperature range 6–330 K has been developed. It uses the vibrating reed technique with amplitude sensing by piezoelements. The measurement is absolute because the magnetic moment of the sample is compensated by a loop current that is adjusted with a zero detection circuit. Dia-, para-, and ferromagnetic contributions can be evaluated simultaneously. The resolution for measuring magnetic moments is better than 10−7 emu, corresponding to a susceptibility of 10−11 cm3 at 10 kOe. Magnetic measurements of thin ferromagnetic films, diluted paramagnetic systems, and a superconducting material are presented to demonstrate the sensitivity and versatility of the system.