A new ordered oxygen-deficient perovskite Sm₂Sr₆Cu₈O_17+δ: HREM Study of PLD Thin Films

A new ordered perovskite phase, Sm2Sr6Cu8O17+δ, has been synthesized by reflection high-energy electron diffraction monitored pulsed laser deposition technique. It exhibits a supercell with a ∼ b ∼ 2ap 2 = 10.89 A ̊; and c = 3.66 Å. A novel structure whose framework is built up from the intergrowth of [CuO2]∞ and [Cu4O9]∞ chains running along [010]p and a Sm/Sr ordering is proposed from the electron microscopy observations. The analyses of the structure and the extended defects which arise in the matrix suggest that it should be possible to stabilize new intergrowths of SrCuO2 and SmSr3Cu4O9 structures. © 1995 Academic Press.