Magnetiseringsgren

Magnetiseringsgren, in the context of magnetism, refers to the magnetisation branch of the magnetic field versus magnetisation relationship for a material, typically shown on an M–H or B–H plot. It describes how the internal magnetisation M responds to an externally applied magnetic field H under specified conditions, usually at a fixed temperature.

In ferromagnetic materials, the response is history dependent, and the M–H relationship forms a hysteresis loop. The curve contains distinct branches corresponding to increasing and decreasing applied field, producing an upper and a lower magnetiseringsgren. As H is increased from zero, domains realign and M rises toward saturation; when H is reduced and reversed, M follows a different path, producing the loop.

Key characteristics associated with magnetiseringsgren include saturation magnetisation Ms, where further increases in H produce little additional magnetisation; coercive field Hc, the field required to bring M to zero on demagnetisation; and remanent magnetisation Br, the residual magnetisation when H is zero after saturation. The slope in the initial, linear region reflects the material’s initial susceptibility, and the area inside the loop is related to energy losses during a magnetisation cycle.

Measurement and analysis of magnetiseringsgren curves are used to characterize magnetic materials for electrical machines, transformers, data storage, and magnetic sensors. The curves can be plotted as M versus H or as B versus H, using the relation B = μ0(H + M).