Magnetic Properties Of Solids

Every substance around us has some magnetic properties in it. Different types of materials show different properties in the presence of magnetic field. The magnetic properties of a substance originate from the electrons present in the atoms or molecules. Every electron in an atom behaves like a small magnet. Electrons can also be referred to as small loops of current which retain their magnetic moment.

Magnetic properties

These magnetic moments come from two types of motion of electrons:

1. The orbital movement around the nucleus of an atom.
2. When the electron spins around its own axis.

On the basis of the magnetic properties solids can be classified as follows:

 Properties Description Alignment of magnetic dipoles Examples Application Diamagnetic They are weakly repelled by the magnetic fields All the electrons in the orbitals are paired and are completely filled. NaCl, Benzene Behaves like an insulator. Paramagnetic They are weakly attracted by the magnetic fields. Contains at least one unpaired electron in the orbital. O2, Cu2+ etc. Electronic appliances Ferromagnetic Strongly attracted by the magnetic field. The can be magnetised permanently Consists of unpaired electrons, all having the same direction Cobalt, nickel, CrO2 etc. CrO2 is commonly used in making cassette recorder. Antiferromagnetic Net magnetic moment is zero. Dipole moments are arranged in a compensatory way NiO, MnO, V2O3 etc. – Ferrimagnetic Possess small net magnetic moments Unequal number of parallel and antiparallel arrangement of magnetic moments Fe3O4 –

Graphs showing the variation of magnetic properties on changing temperature:

In paramagnetic material, with the increase in magnetic field, the magnetization of the material increases. When the material is heated the magnetization starts decreasing, so the magnetization of material is inversely proportional to temperature. This relationship is known as Curie’s law.

$M$ = $C × \frac{B}{T}$

Where, M = magnetization of material

C= Curie’s constant

B= applied magnetic field

T= Temperature

Fig. Graphs showing effect of temperature on magnetization of materials.

In this article we discussed about the magnetic properties of solids. To know about the electrical properties and dielectric properties of solids. For more information download Byjus-The Learning App’

Practise This Question

Which of the following is paramagnetic in nature?