Diamagnetic substances are those in which the net magnetic moment of atoms is zero.
- The susceptibility has a low negative value. (For example, for bismuth Xm = – 0.00017).
- Susceptibility is independent of temperature.
- The relative permeability is slightly less than one.
- When placed in a non-uniform magnetic field they have a tendency to move away from the field, (i.e) from the stronger part to the weaker part of the field. They get magnetized in a direction opposite to the field as shown in the Figure.
- When suspended freely in a uniform magnetic field, they set themselves perpendicular to the direction of the magnetic field (Figure).
Examples: Bi, Sb, Cu, Au, Hg, H2O, H2 etc.