1. Classes of Magnetic Materials

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

3. 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

4. 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

5. 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

6. Magnetic Domains cause of the strong magnetic property of ferromagnetic materials region of 10 12 to 10 15 atoms when magnetic moments of these atoms are aligned parallel the material is said to be “magnetized”

7. Magnetized vs unmagnetized