Temperature dependence of the hyperfine parameters on Fe3O4(111) surfaces

The Verwey transition on Fe3O4(111) surface was investigated using nuclear resonant x-ray scattering (NRS). Measurements were conducted below (85 K) and above (297 and 500 K) the Verwey transition temperature. The internal magnetic field estimated from the NRS frequency spectra agreed with that of bulk Fe3O4 at all measured temperatures. A clear change in the intensity ratio of the two peaks in the frequency spectra was observed across the Verwey transition. The results indicate that despite the presence of the peculiar surface electronic states which makes the changes in the electronic properties across the Verwey transition temperature blurred, the hyperfine parameters of the (111) surface show a clear change across the Verwey transition temperature.