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Ferroika (from Latin : ferrum = iron) is the generic term for all materials with a spontaneous long-range order. The group of ferroic ordering phenomena includes ferromagnetism , ferroelectricity , ferroelasticity and ferrotoroidicity .

If two or more of the ferroic order phenomena occur simultaneously in a substance, one speaks of a higher order ferroica or multiferroica . Ferroica are therefore of the order one, if there are two orders there is a second order ferroic.

The term Ferroika was introduced in 1970 by the Japanese physicist K. Aizu . The aim was a systematic description and classification of ferromagnetic , ferroelectric and ferroelastic materials, which was essentially based on arguments of symmetry. More recently, ferrotoroidity has been added as the fourth ferroic order.

Individual evidence

  1. K. Aizu, Possible Species of Ferromagnetic, Ferroelectric, and Ferroelastic Crystals , Phys. Rev. B, 2, 754, 1970 .