Heusler alloy

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A Heusler alloy is a ferromagnetic metal alloy based on a Heusler phase. Heusler phases are intermetallics with particular composition and fcc crystal structure. They are ferromagnetic even though the constituting elements are not as a result of the increased separation of the magnetic elements, usually manganese which sit at the body centers in a Heusler alloy. The magnetic moment usually resides almost solely on the manganese atom in these alloys. See the Bethe-Slater curve for more info on why this happens.

The term is named after a German mining engineer and chemist Friedrich Heusler, who studied such an alloy in 1903. It contained two parts copper, one part manganese, and one part tin.

In recent time, the importance of Heusler alloys for spintronics has been increasing.

Another useful Heusler alloy is the class of materials known as ferromagnetic shape memory alloys which can change their length by up to 10% on application of a magnetic field. These are generally an alloy of nickel-manganese-gallium.

[edit] References

• Ferromagnetism, from The Physics Hypertextbook
• G. Sauthoff: Intermetallics, Wiley-VCH, Weinheim 1995, S. 83 u. 90.

[edit] External links

• National Pollutant Inventory - Copper and compounds fact sheet