Types of Magnetism 

Diamagnetism

This appears in all materials. Diamagnetism is the inclination for a material to oppose an applied magnetic field, therefore repelling it. However, in a material with paramagnetic properties (that is, with a tendency to enhance an external magnetic field), the paramagnetic behaviour dominates. Diamagnetic behaviour is observed only in a purely diamagnetic material, such as copper and carbon. In a diamagnetic material, there are no unpaired electrons. One of the most important applications of diamagnetism is with magnetic resonance imaging systems, or MRIs. These machines are crucial to our healthcare system as they offer three dimensional images of internal organs, muscles, and bones. They’re used for disease detection and help physicians when it comes to diagnosing and treating patients.

Paramagnetism

In a paramagnetic material there are unpaired electrons. Paramagnetic substances such as aluminum and oxygen are weakly attracted to an applied magnetic field. While paired electrons have their intrinsic magnetic moments pointing in opposite directions, causing their magnetic fields to cancel out, an unpaired electron is free to align its magnetic moment in any direction. When an external magnetic field is applied, these magnetic moments tend to align themselves in the same direction as the applied field, thus reinforcing them. Paramagnetic substances, like manganese, are also used in relation to MRIs. They’ve been shown to enhance brain imaging, allowing for researchers and doctors to study the different regions of the brain and how they connect. 

Ferromagnetism

A ferromagnet has unpaired electrons, however, there’s a want for these magnetic moments to orient parallel to each other in order to maintain a lowered-energy state. Even without an applied field, the magnetic moments of the electrons spontaneously line up parallel to one another. Ferromagnetism only occurs in a few substances, such as iron, nickel, cobalt, and rare-earth metals. Ferromagnetic materials are found in a wide range of devices that we use on an everyday basis, like telephones and speakers. They’re also found in industrial equipment, like electric motors, transformers, and generators.