Jäännösmagnetointina

Jäännösmagnetointina, also known as remanence or residual magnetism, refers to the magnetism that remains in a ferromagnetic material after an external magnetic field has been removed. When a ferromagnetic material is exposed to a magnetic field, its magnetic domains align with the applied field, causing it to become magnetized. Upon removal of the external field, not all of these aligned domains return to their original random orientation. A portion of this alignment persists, resulting in a net magnetic field within the material.

The strength of the remanent magnetization depends on several factors, including the material's properties, such as its coercivity, and the strength of the external magnetic field applied. Materials with high coercivity retain their magnetization more effectively than those with low coercivity. Jäännösmagnetointina is a crucial property in many applications, including permanent magnets, magnetic storage devices like hard drives and magnetic tapes, and in the measurement of geological or archaeological samples to understand past magnetic field conditions. It is also a phenomenon studied in the context of magnetic hysteresis, where the magnetization of a material is plotted against the applied magnetic field. The remanent magnetization is the value of magnetization where the applied field is zero.