Ferrites are ferromagnetic ceramic materials, compounds of iron, boron and barium or strontium or molybdenum. Ferrites have a high magnetic permeability, which allows them to store stronger magnetic fields than iron. Ferrites are often produced as powder, which can be sintered into solid cores. 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. Early computer memories stored data in the residual magnetic fields of ferrite cores, which were assembled into arrays of core memory. Ferrite powders are used in the coatings of magnetic recording tapes. One such type of material is iron (III) oxide.
Ferrite is also known in materials engineering as the purest state of iron (Fe) in the iron-carbon alloying system, where some solubility of other alloying elements may be present. Ferrite is also known as alpha iron which possesses a Body-Centered Cubic (BCC) crystalline structure. Ferrite undergoes a complete phase-change above 723 degrees Celsius into austenite due to the allotropic nature of iron. Ferrite appears white when observed under a microscope and can be identified within the pearlite phase of carbon steels.
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