Mättnadsmagnetisering

Mättnadsmagnetisering, or saturation magnetization in English, refers to the maximum possible magnetic moment per unit volume that a material can exhibit when subjected to a sufficiently strong external magnetic field. This occurs when all the magnetic moments within the material are aligned in the same direction, contributing their full magnetic strength to the net magnetization.

In ferromagnetic and ferrimagnetic materials, the magnetic moments arise from the intrinsic angular momentum of electrons, known as spin. These spins tend to align with each other due to quantum mechanical exchange interactions. Even in the absence of an external field, these materials can possess a spontaneous magnetization below their Curie temperature. However, thermal agitation tends to disrupt this alignment.

Applying an external magnetic field causes the magnetic moments to align with the field. As the field strength increases, more moments align, and the magnetization of the material increases. Eventually, a point is reached where further increases in the external field do not lead to a significant increase in magnetization. This state is called magnetic saturation, and the corresponding magnetization value is the saturation magnetization.

The saturation magnetization is a fundamental material property and is temperature-dependent, decreasing as temperature rises and vanishing above the Curie temperature. It is an important parameter for determining the performance of magnetic devices such as permanent magnets, magnetic recording media, and transformer cores.