Paramagnétiques

Paramagnétiques refers to materials that are weakly attracted to an external magnetic field. This attraction arises from the presence of unpaired electrons in the atoms or molecules of the material. When an external magnetic field is applied, these unpaired electrons align themselves with the field, creating a net magnetic moment that enhances the field.

Unlike ferromagnetic materials, which retain their magnetism after the external field is removed, paramagnétiques only exhibit magnetism in the presence of an external field. Once the field is removed, the magnetic moments of the unpaired electrons randomize due to thermal agitation, and the material loses its magnetism.

The magnetic susceptibility of paramagnétiques is positive but small, indicating a weak attraction. This property is temperature-dependent, typically decreasing with increasing temperature as thermal energy disrupts the alignment of electron spins. Common examples of paramagnétiques include aluminum, platinum, and oxygen. These materials find applications in various scientific and industrial fields, such as magnetic resonance imaging (MRI) and as components in certain types of sensors. The study of paramagnétiques is a fundamental aspect of solid-state physics and materials science, contributing to our understanding of magnetic phenomena.