Strategies to stabilize new oxides in the Sr(n+1)(CoTa)(n)O(3n+1) Ruddlesden-Popper homologous series.
Two new oxides of the Ruddlesden-Popper series have been isolated and structurally characterized in the Sr-Co-Ta-O system. X-ray and electron diffraction and high-resolution electron microscopy show that polycrystalline Sr(3)CoTaO(7) constitutes the n=2 member of a new Sr(n+1)(CoTa)(n)O(3n+1) homologous series, the essential feature of which is the existence of two connected Co/Ta octahedral layers, separated by Sr atoms. Sr(2)CoTaO(6), the n=infinity member of the series, shows a particular short-range ordering of Co and Ta at the octahedral sites leading, as shown by high-resolution electron microscopy, to the disordered intergrowth of simple and double perovskite type domains. Strategies to stabilize new oxides of this series are discussed.
Boulahya
Khalid
K
Dpto. de Química Inorgánica, Facultad de Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain.
Parras
Marina
M
González-Calbet
José María
JM