Pressure-temperature phase diagram of the EuRbFe4As4 superconductor

The pressure dependencies of the magnetic and superconducting transitions, as well as that of the superconducting upper critical field, are reported for single crystalline EuRbFe4As4. Resistance measurements were performed under hydrostatic pressures up to 6.21 GPa and in magnetic fields up to 9 T. Zero-field-cooled magnetization measurements were performed under hydrostatic pressures up to 1.24 GPa under 20 mT applied field. Superconducting transition temperature, Tc, up to 6.21 GPa and magnetic transition temperature, TM, up to 1.24 GPa were obtained and a pressure-temperature phase diagram was constructed. Our results show that Tc is monotonically suppressed upon increasing pressure. TM is linearly increased up to 1.24 GPa. For the studied pressure range, no signs of the crossing of TM and Tc lines are observed. The normalized slope of the superconducting upper critical field is gradually suppressed with increasing pressure, which may be due to the continuous change of Fermi velocity vF with pressure.