Local structural studies of Ba1 − xKxFe2As2 using atomic pair distribution function analysis

Systematic local structural studies of the Ba1 − xKxFe2As2 system are undertaken at room temperature using atomic pair distribution function analysis. The local structure of the Ba1 − xKxFe2As2 is found to be well described by the long-range structure extracted from diffraction experiments, but with anisotropic atomic vibrations of the constituent atoms (). The crystal unit cell parameters, the FeAs4 tetrahedral angle and the pnictogen height above the Fe-plane are seen to show systematic evolution with K doping, underlining the importance of the structural changes, in addition to the charge doping, in determining the properties of Ba1 − xKxFe2As2.