Figure 1

Rietveld plot of the room temperature diffraction pattern of NBT fitted with (a) rhombohedral ($R$3$c$) and (b) monoclinic ($Cc$) structural models. The open circles correspond to the observed pattern, the continuous line between the data points is the fitted pattern, and the vertical bars represent Bragg peak positions. The difference plots are shown at the bottom of the figures. For convenience, the indices in the inset are with respect to the pseudocubic cell. Every reflection appears twice due to the presence of $K$α${}_2$ component in the incident beam.Reuse & Permissions

Figure 2

Selected pseudocubic Bragg profile electrically poled and unpoled NBT. The XRD patterns were recorded on powdered specimens.Reuse & Permissions

Figure 3

Rietveld plot of NBT after the specimen was poled at an electric field of 70 kV/cm. The observed pattern (open circles) was fitted (continuous line through the data point) with the rhombohedral ($R$3$c$) model. The Bragg peak positions are shown with vertical bars.Reuse & Permissions