Order parameters in the Verwey phase transition

Piekarz, P.; Parlinski, K.; Oles, A. M.

Order parameters in the Verwey phase transition

Authors

Piekarz, P.

Parlinski, K.

Oles, A. M.

Description

The Verwey phase transition in magnetite is analyzed on the basis of the Landau theory. The free energy functional is expanded in a series of components belonging to the primary and secondary order parameters. A low-temperature phase with the monoclinic P2/c symmetry is a result of condensation of two order parameters X_3 and Δ_5 . The temperature dependence of the shear elastic constant C_44 is derived and the mechanism of its softening is discussed.
4 pages, 1 figure