High-pressure phase diagram of NdFeAsO0.9 F0.1: Disappearance of superconductivity on the verge of ferromagnetism from Nd moments

Abstract

We investigated transport and magnetic properties of single crystal NdFeAsO0.9F0.1 under hydrostatic pressures up to 50 GPa. The ambient pressure superconductivity at Tc∼ 45.4 K was fully suppressed at Pc∼21 GPa. Upon a further increase of pressure, ferromagnetism associated with the order of the rare-earth subsystem was induced at the border of superconductivity. Our finding is supported by the hysteresis in the magnetization M(H) loops and the strong increase in the field cooled data M(T) toward low temperatures. We also show that the temperature evolution of the electrical resistivity as a function of pressure is consistent with a crossover from a Fermi liquid to non-Fermi liquid to Fermi liquid. The Hall measurements suggest that the multiband electronic structures have changed with pressure, which should also affect the resistivity behavior. These results give access to the high-pressure side of the superconducting phase diagram in the 1111 type of materials.