Order parameters in the Verwey phase transition
arXiv:0801.1420 · doi:10.1088/1742-6596/92/1/012164
Abstract
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 Î_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