A simple bridge to operate an AC susceptometer

We have designed and fabricated an inexpensive AC susceptometer which works around room temperature. The susceptometer uses the principle of a mutual inductance bridge with a null detection algorithm. The bridge was balanced by two digitally controlled stepper motors coupled with two highly linear potentiometers. The susceptometer was tested with double-perovskite structured samples with transition temperatures close to room temperature. The apparatus would be very useful for low-budget research laboratories which deal with magnetic experiments.