The VSM is used to measure magnetic moment of thin film samples. The sample is mounted upon a carbon-fibre rod, which is inserted into a helium flow cryostat and sits between two pick-up coils. The sample is then vibrated at a constant frequency, resulting in a change in magnetic flux through the coils that, according to Faraday’s Law, induces an EMF. The size of the EMF generated in the pick-up coils is proportional to the magnetic moment of the sample.
The Oxford Instruments VSM used in the CM group allows measurements between 1.2 and 300 K and in magnetic fields up to 8 T with a sensistivity of approximately 10 micro-emu.