Magnetism and Matter
14.0 Classification of Magnetic Materials
14.0 Classification of Magnetic Materials
On the basis of their magnetic properties magnetic materials are divided into three categories
(i) Diamagnetic substances
(ii) Paramagnetic substances
(iii) Ferromagnetic substances
| Sr.No | Diamagnetic substances | Paramagnetic substances | Ferromagnetic substances |
1 | These substances when placed in a magnetic field, acquire feeble magnetism opposite to the direction of the magnetic field.
| These substance when placed in a magnetic field, acquire feeble magnetism in the direction of the magnetic field.
| These substance when placed in a magnetic field, are strongly magnetised in the direction of the field.
|
| 2 | These substances are repelled by a magnet. | These substances are feebly attract by a magnet. | These substances are strongly attracted by a magnet. |
| 3 | When a diamagnetic solution is poured into a $ \cup - $ tube and one arm is placed between the poles of strong magnet, the level of solution in that arm is lowered. | The level of the paramagnetic solution in that arm rises.
| No liquid is ferromagnetic. |
| 4 | If a rod of diamagnetic material is suspended freely between two magnetic poles,its axis becomes perpendicular to the magnetic field.
| Paramagnetic rod becomes parallel to the magnetic field.
| Ferromagnetc rod also becames parallel to the magnetic feild.
|
The atoms of a paramagnetic substance contain even number of electrons.
The atoms or molecules of a paramagnetic substance do not possess any net magnetic moment. The atoms of a paramagnetic material contain odd number of electrons.
Every atom or molecule of a paramagnetic substance has its own magnet moment, i.e., its each atom or molecule is a tiny magnet.
In a ferromagnetic substance, there are several tiny regions called domains. Each domain contain approximately $1010$ atoms.
Each domain is a strong magnet as all atoms or molecules in a domain have same direction of magnetic moment.
