Jäännösmagnetisaation

Jäännösmagnetisaatio refers to the residual magnetism that remains in a ferromagnetic material after the external magnetic field used to magnetize it has been removed. This phenomenon is a key characteristic of materials used in magnetic storage and permanent magnets. When a ferromagnetic material is exposed to a magnetic field, its magnetic domains align in the direction of the applied field. Upon removal of the field, some of this alignment persists, creating a net magnetic moment within the material. The strength and permanence of this residual magnetism depend on the material's properties, particularly its coercivity, which is its resistance to demagnetization. Materials with high coercivity, like hard magnetic materials, retain a strong magnetic field and are suitable for permanent magnets. Materials with low coercivity, or soft magnetic materials, lose most of their magnetism when the external field is removed, making them useful for applications like transformer cores where rapid changes in magnetization are required. The measurement of jäännösmagnetisaatio is crucial in quality control for magnetic media and in the design of magnetic devices. It is a fundamental concept in understanding magnetism and its applications.