Cation ordering in (Sr1-xCax)TiO3

Ordering of the A-site cations was observed in (Sr1-xCax)TiO3 for 0.4 less than or equal to x less than or equal to 0.7 by electron diffraction, Strong 1/2{111} reflections are observed for the x = 0.4, 0.5 and 0.6 compositions indicating NaCl-type ordering of the A-sire cations. The presence of 1/2{110} and 1/2{100} reflections are also observed which is probably caused by oxygen octahedra tilting similar to what occurs in CaTiO3. However the 1/2{110} and 1/2{100} reflections for the x = 0.5 composition, have a higher intensity than other compositions, indicating that the octahedra tilting is enhanced by the cation ordering.