Neutron scattering study of the phase transitions in a doped polycrystalline Fe3O4: Zn0.005Fe2.995O4

Abstract

Temperature dependent neutron elastic scattering and resistivity measurements have been made on a polycrystalline sample of Zn0.005Fe2.995O4, which displayed a well-separated, bifurcated, heat-capacity anomaly. The lower-temperature anomaly (near 110 K) was found to be associated with a lattice distortion, but no change in neutron intensity was observed at the higher-temperature anomaly (near 119 K). The electrical resistivity of this sample also exhibited an abrupt change only at the lower-temperature anomaly. The downward shift of the lower-temperature, [lambda]-type anomaly as a result of the very low Zn impurity is, however, confirmed by the neutron scattering results and demonstrates the extreme sensitivity of the structural transition to impurities.