Uses
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Ferrite cores are used in electronic inductors, transformers, and electromagnets where the high electrical resistance of the ferrite leads to very low eddy current losses.
Ferrites are also found as a lump in a computer cable, called a ferrite bead, which helps to prevent high frequency electrical noise (radio frequency interference) from exiting or entering the equipment; these types of ferrites are made with lossy materials to not just block (reflect), but also absorb and dissipate as heat, the unwanted higher-frequency energy.
Early computer memories stored data in the residual magnetic fields of hard ferrite cores, which were assembled into arrays of core memory. Ferrite powders are used in the coatings of magnetic recording tapes.
Ferrite particles are also used as a component of radar-absorbing materials or coatings used in stealth aircraft and in the absorption tiles lining the rooms used for electromagnetic compatibility measurements. Most common audio magnets, including those used in loudspeakers and electromagnetic instrument pickups, are ferrite magnets. Except for certain "vintage" products, ferrite magnets have largely displaced the more expensive Alnico magnets in these applications. In particular, for hard hexaferrites today the most common uses are still as permanent magnets in refrigerator seal gaskets, microphones and loud speakers, small motors for cordless appliances and in automobile applications.[36]
Ferrite magnets find applications in electric power steering systems and automotive sensors due to their cost-effectiveness and corrosion resistance.[37] Ferrite magnets are known for their high magnetic permeability and low electrical conductivity, making them suitable for high-frequency applications.[38] In electric power steering systems, they provide the necessary magnetic field for efficient motor operation, contributing to the system's overall performance and reliability.[39] Automotive sensors utilize ferrite magnets for accurate detection and measurement of various parameters, such as position, speed, and fluid levels.[40]
Due to ceramic ferrite magnet’s weaker magnetic fields compared to superconducting magnets, they are sometimes used in low-field or open MRI systems.[41][42] These magnets are favored in certain cases due to their lower cost, stable magnetic field, and ability to function without the need for complex cooling systems.[43]
Ferrite nanoparticles exhibit superparamagnetic properties.
