Verwey transition in spin polarization of field-emitted electrons from 〈1 1 0〉-oriented single crystal magnetite whisker

We measured temperature dependence of a spin polarization of field-emitted electrons from a single-crystalline magnetite (Fe 3 O 4 ) whisker with 〈1 1 0〉 orientation. The spin polarization of emitted electrons began to increase above 130 K corresponding to the temperature of Verwey point ( T v ). The increase is considered as reflection of the change of the spin state near the Fermi level due to the Verwey transition. Our experimental results support a localization of t 2g orbital electrons below the Verwey point and a model of charge ordering for magnetite.