Pressure effects on Tc of iron-based layered superconductor LaTMPO (TM Fe, Ni)

Abstract

We report electrical and magnetic properties of LaTMPO (TM Fe, Ni) under high pressures. From resistivity measurements, superconducting transition temperature Tc for LaFePO and LaNiPO increases steeply up to about 0.8 GPa, and the dTc/dP values are more than 4 K/GPa and 1 K/GPa, respectively. From the results of high-pressure x-ray diffraction measurements, the oxypnictide compounds show an anisotropic compression along a-axis and c-axis. © 2009 IOP Publishing Ltd.