Diffuse scattering in nd-ce-sr-cu-o

Detailed features of the structural disorder in Nd-Ce-Sr-Cu-O with the T*-structure have been investigated by diffuse scattering in electron diffraction. There exist three types of characteristic diffuse scatterings: a cylindrical-shape, a spike-shape, and spots in addition to the fundamental spots due to the T*-structure. The cylindrical-shape and spike-shape scatterings can be concluded to result from both atomic displacements of 0(2) atoms along the <110> directions, on planes through the apical positions of the CuO₅ pyramids, and the ordering of Nd and Sr atoms. On the other hand, the extra spots are understood to be related to displacements of O(1) or O(3) atoms along the c axis.