Paramagnetism

Paramagnetic substances can only become magnetic if generated by and externally applied field. Paramagnets do not retain any magnetic properties after the externally applied field has been removed. This is the result of the thermally generated motion causing the direction of the electron rotation of the atoms to become random with no net orientation in any direction. Even when situated in a magnetic field only a relatively small net proportion the electron spins become aligned with the field. Common paramagnetic materials are tungsten, aluminum, magnesium and sodium.