On the basis of Magnetic Properties, different materials have been classified into three categories :
Diamagnetic substances are those in which the individual Atoms / Ions / Molecules do not possess any net magnetic moment on their own.
These are feebly magnetized in a direction opposite to that of the magnetizing field in which they are placed, e.g., Bismuth, Antimony, Copper, Gold, Quartz, Mercury, Water, Alcohol, Air, Hydrogen etc.
Paramagnetic substances are those in which each individual Atom / Molecule / Ion has a net non-zero magnetic moment on its own.
These are weakly magnetized in the direction of the magnetizing field in which they are placed, e.g., Al, Pt, Cr, manganese, crown glass, O2 etc.
Ferromagnetic substances are those in which each individual Atom / Molecule / Ion has a non – zero magnetic moment on its own.
These are magnetized strongly in the direction of the magnetizing field in which they are placed.
They show all the properties of paramagnetic substances to a much greater degree.
At certain temperature, ferromagnetic passes over to paramagnetic.
This transition temperature is called Curie temperature.
For soft iron Curie temperature is 1000 K. e.g., iron, cobalt, nickel, and a number of their alloys.
Application Form Submission 16 Dec 2020 to 16 Jan 2021.