Para-magnetic substances are those materials which when placed in magnetic field becomes weakly magnetized in the direction of the external field. Some examples of paramagnetic substances are platinum, aluminium, chromium, manganese, copper sulphate, liquid oxygen etc. When a paramagnetic bar is placed in the magnetic field , the magnetic flux density in it is greater than the magnetic flux density in the vacuum. Thus the relative permeability of the paramagnetic substances is slightly greater then 1. The magnetic flux density due to magnetization is small but positive. The susceptibility of these substances decreases with increase in temperature. Paramagnetic substances are used in the measurement of low temperature.
- A paramagnetic bar , suspended between the poles of a magnet shows opposite poles to those of the magnet in its end.
- Paramagnetic substances have a tendency to move from weaker to the stronger parts in a non-uniform magnetic field.
- Paramagnetic substances obeys Curie’s law