Ion scattering from the single-crystal magnetite Fe3O4 under the Verwey transition

Energy spectra of ions scattered from a cleaved surface of a single-crystal Fe3O4 at small scattering angles were investigated. The magnetite Fe3O4 shows the Verwey transition around 120 K corresponding to the transition from dynamic disorder to long-range order in the distribution of Fe2+ and Fe3+ ions in octahedral sites. This transition is accompanied by a structural transition from cubic FCC to a monoclinic structure. The ion scattering intensity (I) as well as the ion scattering yields (R+) are found to increase by 1.4 and 1.7 times from 295 to 95 K for Ar+ and Ne+ ion scattering, respectively. Around the Verwey temperature, a broad minimum followed by a small maximum was observed in the temperature-dependence curve I(T)and R+ (T). The observed change in the ion scattering under this transition is due to the increase of the neutralization probability and the change of the target material transparency. (C) 1999 Elsevier Science Ltd. All rights reserved.