Magnetoituvia

Magnetoituvia are substances that can acquire a magnetic moment when placed in a magnetic field. The degree of magnetization depends on the material and on the strength, direction, and history of the applied field. They are commonly characterized by magnetic susceptibility χ and relative permeability μr, and for small fields the magnetization is often approximated by M = χH, though real materials exhibit nonlinear and hysteretic behavior.

Based on their response to magnetic fields, magnetoituvia are grouped into diamagnetic, paramagnetic, and ferromagnetic materials. Diamagnetic materials develop a weak, negative magnetization opposite to the applied field and do not retain magnetization after the field is removed. Paramagnetic materials show a weak positive magnetization that disappears when the field is removed. Ferromagnetic materials exhibit strong magnetization with a domain structure; they can retain magnetization (remanence) and show hysteresis, coercivity, and saturation.

In ferromagnets, magnetic moments align within domains due to exchange interactions; external fields align domains, leading to a saturation magnetization at high fields. Temperature affects magnetization: many ferromagnets lose their ferromagnetism above the Curie temperature.

Typical magnetoituvia include iron, nickel, cobalt, as well as alloys and compounds such as neodymium-iron-boron magnets. Soft magnetic materials (steel, ferrites) are optimized for easy magnetization and demagnetization, while hard magnetic materials are used to store persistent magnetization.

Applications span transformers, electric motors, magnetic data storage, sensors, and medical imaging magnets. Characterization relies on B–H and M–H curves, magnetic susceptibility measurements, and specialized magnetometers.