抄録
Crystal structure, structural disorder and hydration behavior of Ca7ZrAl6O18 were investigated by laboratory X-ray powder diffraction (CuKα1) and conduction calorimetry. The initial structural model was determined using direct methods, and it was further modified to a split-atom model, in which the five types of Ca atoms and four types of AlO4 tetrahedra were, respectively, positionally and orientationally disordered. The crystal structure is orthorhombic (space group Pmn21, Z = 2) with lattice dimensions a = 1.08486(1) nm, b = 1.05913(1) nm, c = 0.766945(8) nm and V = 0.88123(1) nm3. The electron density distribution was determined by the maximum-entropy methods-based pattern fitting method.
