{"id":5183,"date":"2026-07-22T09:49:10","date_gmt":"2026-07-22T09:49:10","guid":{"rendered":"https:\/\/faradyi.com\/?p=5183"},"modified":"2026-07-22T09:49:14","modified_gmt":"2026-07-22T09:49:14","slug":"what-is-a-permanent-magnet-how-it-works-types-and-uses","status":"publish","type":"post","link":"https:\/\/faradyi.com\/fr\/what-is-a-permanent-magnet-how-it-works-types-and-uses\/","title":{"rendered":"What Is a Permanent Magnet? How It Works, Types and Uses"},"content":{"rendered":"
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A permanent magnet is a material that produces and retains its own magnetic field without needing a continuous electrical power supply.<\/strong> It has two magnetic poles\u2014north and south\u2014and continues to attract or repel other magnetic materials after the external magnetizing force has been removed.<\/p>\n

Permanent magnets are found in electric motors, generators, speakers, sensors, tools, medical equipment, consumer electronics, and many other products. Their performance depends on the magnetic material, temperature, shape, operating environment, and resistance to demagnetization.<\/p>\n

This guide explains what a permanent magnet is, how it works, the main material types, how it differs from an electromagnet, and what engineers should consider when selecting permanent magnets for motors and other applications.<\/p>\n

Quick answer:<\/strong> A permanent magnet retains a useful magnetic field without continuous electrical input. Common permanent-magnet materials include neodymium-iron-boron, samarium-cobalt, ceramic ferrite, and Alnico.<\/div>\n

What Is a Permanent Magnet?<\/h2>\n

A permanent magnet is an object made from a magnetically hard material that remains magnetized after the field used to magnetize it is removed. Unlike an electromagnet, it does not require current flowing through a coil to maintain its magnetic field.<\/p>\n

The word \u201cpermanent\u201d does not mean that the magnet can never weaken. It means the material is designed to retain a useful level of magnetization for a long time under its specified operating conditions. Excessive temperature, a strong opposing magnetic field, corrosion, mechanical damage, or an unsuitable magnetic circuit can reduce its performance.<\/p>\n

Every permanent magnet has a north pole and a south pole. Opposite poles attract, while like poles repel. If a magnet is divided into smaller pieces, each piece forms its own north and south poles rather than producing an isolated magnetic pole.<\/p>\n

How Does a Permanent Magnet Work?<\/h2>\n

Magnetism originates from the magnetic moments associated with electrons. Inside a ferromagnetic or ferrimagnetic material, groups of atomic magnetic moments can align in regions known as magnetic domains.<\/p>\n

In an unmagnetized material, many domains point in different directions, so their magnetic effects largely cancel one another. During magnetization, a sufficiently strong external magnetic field encourages more domains to align in a preferred direction.<\/p>\n

A permanent-magnet material has high resistance to having that alignment reversed. After the external magnetizing field is removed, much of the alignment remains, allowing the object to produce a persistent external magnetic field.<\/p>\n

Three important properties help engineers compare permanent-magnet materials:<\/p>\n