Morin transition

Synonym: spin-flop transition

A transition specific to α-Fe2O3 in which there is a change in the direction of the atomic magnetic moments in the antiferromagnetic state from parallel to perpendicular to the c-axis. Synonymous with spin-flop transition.
Source:
PAC, 1994, 66, 577 (Definitions of terms relating to phase transitions of the solid state (IUPAC Recommendations 1994)) on page 587