Crystal structure of hexagonal SrAl2O4 at 1073 K

摘要

The crystal structure of SrAl2O4 at 1073 K was determined from conventional X-ray powder diffraction data using direct methods, and it was further refined by the Rietveld method. The structure was hexagonal (space group P6(3), Z = 6) with a = 0.89260(3) nm, c = 0.84985(2) nm and V = 0.58639(3) nm(3). Final reliability indices were R-wp = 7.87%, R-P = 5.87% and R-B = 4.19%. The [AlO4] tetrahedra are linked to form trigonally distorted rings and they are joined in layers. These layers are stacked with a two-layer repeat and connected by the tetrahedral apices. All of the Sr atoms occupy the centers of the rings when viewed along the c-axis. The structure is described as a stuffed derivative of tridymite. (c) 2005 Elsevier Inc. All rights reserved.