sähkömagnetostimulaatioiden

sähkömagnetostriction is a physical phenomenon observed in ferromagnetic materials where the material undergoes a change in shape or dimensions when subjected to a magnetic field. Conversely, when the material is mechanically strained, it produces a magnetic field. This effect is a direct consequence of the coupling between the magnetic and mechanical properties of the material.

The underlying mechanism involves the rearrangement of magnetic domains within the material. In a ferromagnetic material, magnetic domains are regions where the magnetic moments of atoms are aligned. When an external magnetic field is applied, these domains tend to align with the field, causing an overall magnetization of the material. This reorientation of magnetic moments influences the crystalline structure of the material, leading to a change in its macroscopic dimensions. The magnitude of the sähkömagnetostriction effect varies greatly depending on the material. Some materials, like iron and nickel, exhibit significant sähkömagnetostriction, while others show negligible effects.

The inverse effect, known as the magnetostrictive effect or the Villari effect, is equally important. When a magnetostrictive material is subjected to mechanical stress, its magnetic properties, such as magnetic permeability, change. This is because the applied stress can alter the alignment of magnetic domains, affecting how easily the material can be magnetized.

sähkömagnetostriction has numerous practical applications. It is the principle behind many sensors and actuators, including sonar transducers, microphones, speakers, and various types of magnetic sensors used in industry and automotive applications. Devices that utilize sähkömagnetostriction are often referred to as magnetostrictive transducers. Materials like Terfenol-D, which is an alloy of terbium, dysprosium, and iron, are known for their particularly strong magnetostrictive properties, making them suitable for high-performance applications.