A universally applicable composite modulated structure approach to ordered BaxMyTi8−yO16 hollandite-type solid solutions

A wide range of barium titanate hollandites of the form Bax2+Mx2+Ti8-x4+O16 (M=Zn, Co, Mg, Fe and Mn) and Bax2+M2x3+Ti8-2x4+O16 (M=Fe) with nominal x ranging from 1.0 to 1.4 have been synthesized and examined to investigate the solid solution range and the nature of the ordering of the Ba ions. Electron diffraction studies confirm that the barium titanate hollandites are composite modulated single phase solid solutions made up of mutually incommensurable (along b) framework and Ba ion sub-structures. The overall superspace group symmetry was found to be I′2/m(0,x2,0)1. The symbol I′ here refer... Mehr ...