A linear/quadratic order parameter coupling description of the Verwey transition in magnetite, Fe₃O₄.

ABSTRACT: The change in symmetry Fd3m → Cc at the Verwey transition in magnetite puts it in a class of phase transitions with linear/quadratic coupling between two separate order parameters. Direct coupling between an order parameter Q_e, to represent an electronic instability, and an order parameter Q_co, to represent cation charge ordering, has the form λQ_eQ_co², with T_c(Q_e) < T_c(Q_co), but there must also be indirect coupling through the common strain, e₆, due to strain coupling terms λe₆Q_e and λe₆Q_co². Q_e has the symmetry of irrep Γ₅⁺ while the pattern of cation charge ordering of Fe²⁺ and Fe

SUBMITTER: Carpenter MA 

PROVIDER: S-EPMC12322932 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature