Absence of superconductivity in single-phase CaFe2As2 under hydrostatic pressure

Recent high-pressure studies found that structural/magnetic phase transitions are very pressure sensitive in CaFe2As2 and that superconductivity can be achieved under modest pressure, although details of the sharpness and temperature of transitions vary between liquid medium and gas medium measurements. To better understand this issue, we performed high-pressure susceptibility and transport studies on CaFe2As2, using helium as the pressure …