Analyzing the atomic pair distribution function of BMT-based nanopowders via X-ray diffraction

Abstract In this study, we investigate the three-dimensional atomic structure of 0.65[Ba(Mg 1/3 , Ti 2/3 )]−0.35[BaTiO 3 ] (BMT-BT) using x-ray diffraction (XRD) with molybdenum radiation (MoK α 1 ), Rietveld refinement, and the atomic pair distribution function (PDF) technique. We provide an analysis of the advantages of the PDF method for studying the unit cell of electroceramics. The XRD results show that BMT has a bulk crystal structure with a cubic perovskite structure. The new structural information enhances our understanding of the dielectric properties of BMT. The PDF analysis reveals that the average interatomic bond distance in the octahedral TiO 6 atomic bond is around 2.8 Å, and the first peak at r = 1.39 Å corresponds to the nearest neighbor M-O distance (M = Ti, Mg, Nb). Additionally, the peak at r = 2.4 Å corresponds to the Ba-O and O-O distances in the MO 6 octahedron. Peaks in the PDF data below 1 Å are ignored as they have no physical implications.