Papers by Keyword: Mott-Insulator

Abstract: We report here on resistive switching measurements on GaMo₄S₈ a lacunar spinel compound with tetrahedral Mo₄ clusters filled with 11 electrons. Alike other clustered lacunar spinel compounds with 7 or 8 electrons per cluster, this narrow gap Mott Insulator exhibits both a volatile and a non-volatile unipolar resistive switching. We found that the volatile resistive switching appears above a threshold electric field in the 7 kV/cm range. For electric field much larger than this threshold, the resistive switching becomes non-volatile. Successive electric pulses allow switching back and forth between high and low resistance states. All these results demonstrate that the narrow gap Mott insulator compound GaMo₄S₈ could be a relevant candidate for a new type of non-volatile memory based on an electric field induced breakdown of the Mott insulating state.

Abstract: TlFe2Se2-δ was synthesized by a self-flux method with excess amount of selenium. Elemental analysis using energy-dispersive X-ray spectroscopy estimates the deficiency δ at about 0.5. The magnetic susceptibility reveals an antiferromagnetic transition at TN ≈ 475 K. The resistivity exhibits a semiconducting behavior with an activation energy, EA = 0.04 eV. There is a clear anomaly in the resistivity at TN, indicating a strong interplay between magnetism and electric conduction.