A long-period superstructure in the Bi2O3-V2O5 system

Abstract

The structure of ternary bismuth oxides has been investigated using X-ray photographic methods. A long-period structure was observed in the compound 9Bi 2 O 3 -1V 2 O 5 . It has a defect fluorite structure containing 21 x 3 x 3 cells. The structure is derived from a 3 x 3 x 3 superstructure, where V atoms are located at every third layer along the [111] axis. The crystal has a structure with three modulations, each propagating along the [111], [111] and [111] axes, where periodic one-third slips occur at every seventh layer.