Layered perovskitic structures in pure and doped LaTiO_3.5-x and SrNbO_3.5-x

The effect of careful control over metal and oxygen stoichiometry on the structures of various Mn+1M′n+1 O3n+5 phases (M = La and/or Sr, M′ = Ti and/or Nb) has been studied by transmission electron microscopy. In addition to the previously reported n = 3 and 4 layered phases and the n = ∝ parent perovskite, ordered and disordered intergrowth structures comprising the n = 2, 3, 4, and ∝ members have been characterized. The effects of in situ reduction in the electron microscope were studied. © 1993 Academic Press, Inc.