MAGNETIC MATERIALS – DIPOLE MOMENT
Materials which has got the ultimate capacity of attracting pieces of Iron, nickel, cobalt , dyasporium when they are subjected to external field can be noticed as an important property of magnetic materials. Magnetic materials will not exist as a monopole they always exist as a dipole, because even if we break the magnetic material into pieces the tiny pieces of magnet will also behave as a dipole. Actually the dipole in a magnet is formed due to two reasons
1. Orbital Motion 2. Spin motion of electron
We know that electron revolves round the nucleus in definite circular orbits and with consistent ...view middle of the document...
2. Ferromagnetic materials.
3. Paramagnetic materials.
4. Antiferromagnetic materials.
5. Ferrimagnetic materials.
1. Diamagnetic materials :- There are certain class of materials which cannot allow the magnetic lines of force to penetrate into the material there may be different reasons one is due to the negative susceptibility of the material i.e incapability of the material to allow magnetic lines of force, the another reason is diamagnetic materials themselves contains a small perpetual currents called persistent currents, this persistent currents inside the material will generate small magnetic field opposite to the direction of the external magnetic field as a result of this magnetic lines of force will draw away from the material. Hence diamagnetic materials are not much used in our daily life because of its negative susceptibility. The alignment of atoms in the diamagnetic materials is as shown below.
2. Ferromagnetic materials :- Materials which are strongly attracted to the external magnetic field are called ferromagnetic materials, ferromagnetic materials show strong magnetisation due to the presence of a) spontaneous magnetisation b) Hysterisis
Spontaneous magnetisation is a property where the magnetisation will be present in the material even in the absence of the external magnetic field.
In general a ferromagnetic material is divided into small regions called domains, domains are the regions where the spins of electrons are aligned in same direction, but when we consider the total volume of the material the net magnetisation of material is zero because in each domain of the ferromagnetic material some set of spins will be in anticlock and remaining will be in clockwise direction. When we apply the external magnetic field to this ferromagnetic material they react strongly to the field, because ferromagnetic materials strongly...