Hydrostatic and uniaxial pressure dependence of superconducting transition temperature of KFe2As2 single crystals

We present heat capacity, c-axis thermal expansion and pressure-dependent, low-field, temperature-dependent magnetization for pressures up to similar to 12 kbar, data for KFe2As2 single crystals. T-c decreases under pressure with dT(c)/dP approximate to -0.10 K/kbar. The inferred uniaxial, c-axis, pressure derivative is positive, dT(c)/dp(c) approximate to 0.11 K/kbar. The data are analyzed in comparison with those for overdoped Fe-based superconductors. Arguments are presented that superconductivity in KFe2As2 may be different from the other overdoped, Fe-based materials in the 122 family. DOI: 10.1103/PhysRevB.86.224514