Synthesis and structure of the layered quadruple perovskite Tb2Ba2Cu2Ti2O11

Abstract

The synthesis, structure, and high-resolution transmission electron microscopy studies of the layered quadruple perovskite Tb2Ba2Cu2Ti2O11 are reported. This oxide represents the limit of the series Ln2 Ba2Cu2Ti2O11, Tb being the smallest lanthanide compatible with the stability of the ap x ap x 4ap superstructure observed (ap = cubic perovskite cell length). This structure was confirmed by powder X-ray diffraction profile analyses, electron diffraction, and high-resolution electron microscopy. The Cu-O (basal) bond distance of 1,947(3) Å and the Cu-O-Cu bond angle of 169(1)° are the best suited within this series of oxides to the attainment of superconductivity upon appropriate p-doping.