Classes of Magnetic Materials

Magnetic susceptibility

quantitative measure of the extent to which a material may be magnetized in relation to a given applied magnetic field

Diamagnetic

have a weak, negative susceptibility to magnetic fields.

slightly repelled by a magnetic field does not retain the magnetic

properties when the external field is removed

most elements in the periodic table, including copper, silver, and gold

Paramagnetic

have a small, positive susceptibility to magnetic fields

slightly attracted by a magnetic field does not retain the magnetic

properties when the external field is removed

magnesium, molybdenum, lithium, and tantalum

Ferromagnetic

have a large, positive susceptibility to an external magnetic field

exhibit a strong attraction to magnetic fields

able to retain their magnetic properties after the external field has been removed

strong magnetic properties due to the presence of magnetic domains

iron, nickel, and cobalt

Magnetic Domains

cause of the strong magnetic property of ferromagnetic materials

region of 1012 to 1015 atoms when magnetic moments of these

atoms are aligned parallel the material is said to be “magnetized”

Magnetized vs unmagnetized