Final answer:
Diamagnetic materials, such as copper and bismuth, possess no net magnetic moment and are characterized by a repulsive response to external magnetic fields. This is due to their paired electrons and the resultant opposite alignment of their induced magnetic dipoles to the applied magnetic field.
Step-by-step explanation:
Diamagnetic materials are known for their unique magnetic properties. Unlike ferromagnetic materials like iron or cobalt, diamagnetic substances cannot sustain any permanent magnetization. Their magnetic dipoles create an induced magnetic field that is oriented oppositely to any external magnetic field applied, leading to a negative magnetic susceptibility. When an external magnetic field is present, it induces a dipole moment in the atoms of the diamagnetic material, which then align in the opposite direction to the field. As a result, diamagnets are weakly repelled by a magnetic field, a behavior distinct from both ferromagnetic and paramagnetic materials.
Examples of diamagnetic materials include copper and bismuth. Unlike paramagnetic substances like aluminium, which are attracted to magnetic fields but lose their magnetism when the field is removed, diamagnetic materials are always repelled and never attracted to a magnetic field. Furthermore, because all their electrons are paired and spin in opposite directions, these materials possess no net magnetic moment; their response to magnetic fields is only due to the induced dipoles.