Explain Properties of Paramagnetic Substances

Paramagnetic substances are those in which each atom or molecule has a net non-zero magnetic moment of its own.

1. Susceptibility has a low positive value. (For example: X_m for aluminium is +0.00002).
2. Susceptibiltity is inversely proportional to absolute temperature (i.e) X α 1/T. As the temperature increases susceptibility decreases.
3. The relative permeability is greater than one.
4. When placed in a non uniform magnetic field, they have a tendency to move from weaker part to the stronger part of the field. They get magnetised in the direction of the field as shown in Figure.

5. When suspended freely in a uniform magnetic field, they set themselves parallel to the direction of magnetic field (Figure).

Examples: Al, Pt, Cr, O₂, Mn, CuSO₄ etc.