Macroscopic strain-coupling induced symmetry change in Fe3O4

The Verwey transition in Fe₃O₄ at 120°K is accompanied by symmetry change believed to be from cubic to orthorhombic,¹ although the exact symmetry of the low temperature magnetite as revealed by recent neutron-diffraction² and electron microscopy³ seems of a symmetry lower than the orthorhombic. In this communication, we shall only be concerned, with the aspects of possible symmetry change necessitated by degeneracy removal of the ground state wave functions, as a result of macroscopic strain coupling of the static Jahn-Teller type. No attempt will be made to include Verwey ordering, which is the object of a future paper.