Magnetic Susceptibility

Gouy's Method

Holmarc's Magnetic Susceptibility - Gouy's Method Apparatus (Model No: HO-ED-EM-08) is designed for the determination of magnetic susceptibility of solid samples. The apparatus consists of a pair of electromagnets with constant current power supply and a tube in which the sample powder is taken. The magnetic field is measured using a digital Gauss meter. The sample weight measurements are taken with the help of a Gouy balance.

In the Gouy's method of susceptibility measurement, the solid sample in the form of a long cylinder is hung from the pan of a balance and is placed in such a way that one end of the sample is between the pole pieces of the magnet and the other one is outside the field. The force exerted on the sample by the inhomogeneous magnetic field is obtained by measuring the apparent gain or loss in sample weight.

A sample with a para magnetic compound will be pulled down towards the magnet and will provide a positive difference in apparent mass. Diamagnetic compounds can either exhibit no apparent change in weight or a negative change, as the sample is slightly repelled by the applied magnetic field. With a para magnetic sample, the magnetic induction is stronger than the applied field and magnetic susceptibility is positive. A diamagnetic sample has a magnetic induction much weaker than the applied field, and a respective negative magnetic susceptibility.

Experiment: