ABSTRACT

Fig 1 High-resolution TEM images and the corresponding SADP’s of grains from PbnNb2C>5+n ceramics with the nominal compositions (a) n = 1.5, (b) n = 1.6, (c) η = 1.75, (d) and (e) n = 2.0, (f) n = 2.2, (g) n = 2.5, and (h) n = 3.0. A simulation of the n = 1.5 structure is shown inset in (a), and outline unit cells are drawn for both the cubic and trigonal settings. Crystallographic directions are labelled with reference to the cubic unit cell.