This paper considers stacking fault disorder in Ba3M1Nb2O9 (M=Mn2+ or Co2+) 1:2 triple perovskites and how best to model it when refining neutron powder diffraction data. The true local structures of both samples were successfully refined using a coherent stacking fault disordered model. The stacking fault disorder in Ba3MnNb2O9 and Ba3CoNb2O9 affects their dielectric properties.
Liu, Y., Withers, R., Ting, V. P., Fitzgerald, J., & Noren, L. (2006). Stacking fault disorder and its diffraction consequences in Ba3MNb2O9 (M=Co and Mn) 1:2 triple perovskites. Physica B: Condensed Matter, 385-386(1), 564-566. https://doi.org/10.1016/j.physb.2006.05.360