Magnetoitu

Magnetoitu is the Finnish term for magnetized, describing a material that has acquired a net magnetic moment through exposure to a magnetic field. In ferromagnetic and ferrimagnetic materials, magnetization is typically caused by alignment of microscopic magnetic domains. The magnetization can be permanent, persisting after the external field is removed, or temporary, decaying when the field is removed. The ease with which a material becomes magnetized and retains magnetization is described by its coercivity and anisotropy.

Permanent magnetization is common in hard magnetic materials with high coercivity. Soft magnetic materials readily align under a field but demagnetize quickly once the field is gone. Magnetic behavior is summarized by the B-H curve, showing how magnetization M responds to applied field H and the presence of hysteresis, remanence, and saturation. As temperature increases toward the Curie temperature, ferromagnetic order weakens and magnetization decreases.

Common magnetized materials include permanent magnets such as NdFeB and SmCo, ferrites, and Alnico groups; soft magnets like silicon steel and ferritic alloys. Magnetic anisotropy, crystal structure and microstructure govern the direction and stability of magnetization. Manufacturing often includes aligning domains through applied magnetic fields or using thermal or mechanical treatments.

Magnetoitu materials are used in data storage, electric machines (motors, generators, transformers), magnetic shielding, sensors, and medical devices. They can lose magnetization due to heat, shock, or opposing fields. The Curie temperature marks the limit beyond which ferromagnetism disappears. Handling and storage require avoiding demagnetizing fields and high temperatures.