A transition between antiferromagnetic and ferromagnetic coupling between two subarrays of magnetic atoms. Example: Ordered
FeRh changes from antiferromagnetic to ferromagnetic coupling with the simple cubic
Fe array in a first-order transition.
Source:
PAC, 1994, 66, 577. 'Definitions of terms relating to phase transitions of the solid state (IUPAC Recommendations 1994)' on page 582 (https://doi.org/10.1351/pac199466030577)