The incommensurate modulated structure of the Bi2Sr2Ca1Cu2Oy high-Tc superocnductor has been studied by direct methods with X-ray diffraction data from a single crystal. The super-space group is N111Bbmb with three-di...The incommensurate modulated structure of the Bi2Sr2Ca1Cu2Oy high-Tc superocnductor has been studied by direct methods with X-ray diffraction data from a single crystal. The super-space group is N111Bbmb with three-dimensional unit cell parameters a = 0.54222 nm, b=0.5437 nm, c=3.0537 run, α=β=γ=90° andthemodula-tion wave vector q=(0, 0.22, 1). 543 main reflections, 867 first-order and 469 second-order satellite reflections have been observed. Phases of main reflections are derived by a conventional direct-method program SAPI91. The phases of satellite reflections are derived by the program DIMS running with default control based on the known phases of main reflections. The atomic parameters of the basic structure and of the modulation so obtained consist with the results from other authors. For the first time the structure details of the incommensurate modulation in the Bi-2212 phase are observed directly without relying on any assumed model of modulation.展开更多
文摘The incommensurate modulated structure of the Bi2Sr2Ca1Cu2Oy high-Tc superocnductor has been studied by direct methods with X-ray diffraction data from a single crystal. The super-space group is N111Bbmb with three-dimensional unit cell parameters a = 0.54222 nm, b=0.5437 nm, c=3.0537 run, α=β=γ=90° andthemodula-tion wave vector q=(0, 0.22, 1). 543 main reflections, 867 first-order and 469 second-order satellite reflections have been observed. Phases of main reflections are derived by a conventional direct-method program SAPI91. The phases of satellite reflections are derived by the program DIMS running with default control based on the known phases of main reflections. The atomic parameters of the basic structure and of the modulation so obtained consist with the results from other authors. For the first time the structure details of the incommensurate modulation in the Bi-2212 phase are observed directly without relying on any assumed model of modulation.
