Evidence for a single-stage Verwey-transition in perfect magnetite

Abstract

Abstract Recently, two specific heat peaks occurring near the Verwey transition (Tv = 125 K) in nominally stoichiometric powdered magnetite (Fe3O4) have been interpreted as representing characteristic intrinsic phenomena in stoichiometric Fe3O4. Magnetic after-effect (MAE) measurements performed on this same material suggest, however, that the lower peak (113 K) originates from lattice defects which have been produced during preparation of the powder from the initial bulk single crystal. Our MAE investigations on perfect Fe3O4 crystals support the single-stage character of the Verwey transition at 125 K.