Diamagnetism

Diamagnetism (from the Greek. Dia ... - discrepancy (of lines of force), and magnetism) is one of the types of magnetism , which manifests itself in the magnetization of matter towards the direction of an external magnetic field acting on it.

Diamagnetism is inherent in all substances. Diamagnetism can be considered as a result of induction currents induced in the filled electronic shells of ions by an external magnetic field. These currents create an induced magnetic moment in each atom, directed, according to the Lenz rule, towards the external field (regardless of whether there was originally an own moment or not and how it was oriented). Diamagnetism, however, cannot be described from the standpoint of only classical physics, it is an extremely quantum-mechanical phenomenon. ^[1] Ideal diamagnetism is non-cooperative in nature and is characterized by negative, temperature-independent magnetic susceptibility. Diamagnetism is part of any magnetic state of matter, but it is usually negligible compared to magnetism due to the presence of spontaneous magnetic moments in the system. In purely diamagnetic substances, the electron shells (molecules) do not have a constant moment. The moments created by individual electrons in such substances in the absence of an external field are mutually compensated. In particular, this takes place in ions and molecules with completely filled electron shells, for example, in inert gases, in molecules.

Examples of purely diamagnetic solids ( diamagnets ) in the class of crystalline metals and dielectrics are Cu and NaCl , respectively, and in the class of amorphous solids, SiO ₂ .