hystereesikilvestä

Hysteresikilvestä refers to a phenomenon observed in ferromagnetic materials where the relationship between the applied magnetic field and the resulting magnetization is not linear and exhibits a dependence on the history of the applied field. This lagging effect is known as magnetic hysteresis.

When a ferromagnetic material is subjected to a progressively increasing magnetic field, its magnetization increases. However, as the field is reduced, the magnetization does not decrease along the same path. Even when the external field is reduced to zero, the material retains some residual magnetization, called remanence. To completely demagnetize the material, a reverse magnetic field, known as the coercive field, must be applied.

The characteristic curve that plots magnetization against the applied magnetic field for a ferromagnetic material is called the hysteresis loop or hysteresikilvestä. The area enclosed by this loop represents the energy lost as heat during each cycle of magnetization and demagnetization. Materials with a narrow hysteresis loop are considered "soft" magnetic materials and are used in applications like transformers and inductors where frequent cycles of magnetization and demagnetization occur, and energy loss needs to be minimized. "Hard" magnetic materials have wider hysteresis loops and higher coercivity, making them suitable for permanent magnets as they retain their magnetization more effectively. The shape and size of the hysteresis loop are important parameters for understanding and selecting magnetic materials for specific technological applications.