Direct observation of localization of the minority-spin-band electrons in magnetite below the Verwey temperature

Abstract

Two-dimensional spin-uncompensated momentum density distributions, ${\ensuremath{\rho}}_{\text{s}}^{2\text{D}}(\mathbf{p})\text{s}$, were reconstructed in magnetite at 12 and 300 K from several measured directional magnetic Compton profiles. Mechanical detwinning was used to overcome severe twinning in the single-crystal sample below the Verwey transition. The reconstructed ${\ensuremath{\rho}}_{\text{s}}^{2\text{D}}(\mathbf{p})$ in the first Brillouin zone changes from being negative at 300 K to positive at 12 K. This result provides the first clear evidence that electrons with low momenta in the minority-spin bands in magnetite are localized below the Verwey transition temperature.