Mágnest

Mágnest refers to a material or object that produces a persistent magnetic field. In general, a mágnest can attract or repel ferromagnetic materials such as iron, nickel, and cobalt, and it can influence nearby magnetic fields. Magnetic behavior arises from the alignment of microscopic magnetic moments within the material. Mágnests are typically categorized as permanent magnets, which maintain their magnetization without power, and electromagnets, which generate a magnetic field when an electric current passes through a coil.

Permanent magnets are made from alloys with strong intrinsic magnetism, including ferrites, neodymium-iron-boron, samarium-cobalt, and aluminum-nickel-cobalt. They are valued for high magnetic energy density and resistance to demagnetization (coercivity). Electromagnets consist of a coil wound around a ferromagnetic core; their field strength is proportional to the current and can be switched on or off.

Key properties include magnetic flux density (B), magnetization (M), and hysteresis, which describes how the magnet's response depends on its history of exposure to fields. The Curie temperature is the temperature above which some mágnests lose their permanent magnetization. Magnetic domains in the material reorient under external fields, leading to magnetization, and the way domains align determines the magnet’s strength and behavior.

Applications span electric motors and generators, magnetic storage and data-tape systems, loudspeakers, MRI machines, and magnetic separation in industry. In daily life, magnets are used in compass needles, refrigerator magnets, and various fasteners. The study of mágnest intersects with broader topics in magnetism, materials science, and electrical engineering.