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Magnetic Materials

MAGETIC MATERIALS

On the basis of magnetic properties like susceptibility and permeability, magnetic materials are categorized in following groups:

Diamagnetic substance: The magnetic substance in which an atom or ion contains paired electrons. The total magnetic moment is practically zero as a result of nullifying effect of the orbital and spin angular moments. It shows magnetic moment anti-parallel to the field. Such substances possess following properties:

      (i) Value of susceptibility, susceptibility is negative and small.

      (ii) Relative permeability, μr <1.

      (iii) susceptibility is independent of temperature.

Examples: Gold, copper, Silver, Diamond, Water, H2 and N2 etc.

Paramagnetic substance: The magnetic substance in which atom or ion has one or more unpaired electrons and thus possesses permanent magnetic moment. Such substances possess following properties:

      (i) Value of susceptibility is positive but very small.

      (ii) Relative permeability μr >1.

      (iii) susceptibility is dependent of temperature.

      (iv) It follows Curie law (= C/T)

Examples: Tungsten, Al, Mn & O2 etc.

Ferromagnetic substance: The magnetic substance in which a strong interaction between adjacent magnetic moments tends to align them parallel to one another is called ferromagnetic. Such substances possess following properties:

        (i) Value of susceptibility is positive and very large.

       (ii) Relative permeability μr >>1.

      (iii) susceptibility is dependent of temperature.

      (iv) It follows Curie law

Examples: Fe, Co & Ni etc.



Also see (Click on these quick links) : 

1. Domain Theory of Ferromagnetism: http://www.askmattrab.com/notes/93-domain-theory-of-ferromagnetism

2. Antiferromagnetic and Ferrimagnet: http://www.askmattrab.com/notes/94-antiferromagnet-and-ferrimagnet

3. Magnetic Materials: http://www.askmattrab.com/notes/95-magnetic-materials

4. Working of the Transformer: http://www.askmattrab.com/notes/97-working-of-the-transformer