Study of the structural characteristics of Bi-Sr-Ca-Cu-O single crystals using the method of crystal rotation

The structural characteristics of single crystals of the Bi-Sr-Ca-Cu-O 2212 superconducting phase have been studied by using the setup of Weissenberg photograph and the plane film. It is observed that the lattice points have been stretched extensively along the c * direction to form reciprocal poles by rotating the crystal around the a axis. It is proved that the single crystal is not a normal definite three-dimensional lattice. It is a stacking layer structure with a two-dimensional lattice. A two-dimensional superlattice on the (001) is formed by a three-dimensional crystal, which is broken up by “Bi-concentrated bands”, and a one-dimensional lattice along the [001] direction with period c =15.40 Å, or c =30.80 Å is formed by the interval arrangement of the two-dimensional superlattices of perovskite-like layers and “Bi-concentrated bands” with each other. It is the crystal structural characteristics of the Bi-Sr-Ca-Cu-O high- T c superconductor that the two-dimensional lattice and one-dimensional lattice are independent of each other, which is closely related with the superconductivity.