püsivmagnetite

Püsivmagnetite, often translated as permanent magnets, are materials that produce their own magnetic field. They are distinguished from electromagnets, which require an electric current to generate their magnetic field, and temporary magnets, which only exhibit magnetism when exposed to an external magnetic field. The magnetic properties of permanent magnets arise from the alignment of their internal magnetic domains. In a non-magnetized state, these domains are randomly oriented, resulting in no net magnetic field. When subjected to a strong external magnetic field, these domains align, and if the material has a high coercivity, it retains a significant portion of this alignment after the external field is removed, thus becoming a permanent magnet.

Common materials used to create permanent magnets include alloys of rare-earth elements such as neodymium-iron-boron (NdFeB) and samarium-cobalt (SmCo), as well as ceramic materials like ferrites. Alnico magnets, an alloy of aluminum, nickel, cobalt, and iron, are another notable type. The strength and properties of a permanent magnet are characterized by parameters such as its remanence (the magnetic flux density remaining after the magnetizing field is removed) and coercivity (the magnetic field strength required to demagnetize the magnet). These magnets are ubiquitous in modern technology, finding applications in electric motors, generators, loudspeakers, magnetic storage devices, magnetic resonance imaging (MRI) machines, and various consumer products. Their ability to provide a constant magnetic field without the need for continuous power makes them essential components in countless devices.