Pressure tuned crystal structure in NdBa2Cu3O6+δ superconductor

Abstract The high-pressure angle-dispersive X-ray diffraction experiments on the NdBa 2 Cu 3 O 6+ δ superconductor were performed from ambient to above 30 GPa at room temperature. The structure analysis based on the Rietveld refinement methods shows the different pressure dependence for the bond length between the basal-plane copper of the pyramids to the apical oxygen (denoted Cu(2)–O(1)) and bond length between basal-plane copper to plane oxygen (denoted Cu(2)–O(2,3)). The ambient bulk modulus B 0 is derived as 127 GPa. A possible correlation between Cu(2)–O(1) and T c was discussed.