
Figure 6
Impact of interstratification on the 00l reflections from a theoretical mixedlayer tobermorite XRD pattern. (top) Different interstratification modes for a binary system containing tobermoritelike layers having 14 and 11 Å basal distances, plotted in a P_{T14T14} versus W_{T14} graph. The structure of the 14 Å layer is that of plombierite, and the structure of the 11 Å layer is that from a MDO2 sample from Urals where all bridging tetrahedra are omitted. Solid line: field of R1 maximum possible degree of order (R1 MDPO), dotted line: field of R0 (random interstratification). Between these two lines lies the field of partial ordering, and above the R0 field lies the partial segregation field. Segregation is reached when P_{T14T14} = 1. The area below the MPDO field is a nonphysical field. Dots labelled 19 represent the nine calculations performed in the bottom figure: 13 are calculations performed in the R0 hypothesis (b in the bottom figure, with W_{T14} = 0.2, 0.5 and 0.8 for calculations 1  solid line, 2  dashed line and 3  dashdotted line), 46 calculations in the R1 MPDO hypothesis (c in the bottom figure, W_{T14} = 0.5, 0.7 and 0.9 for 4  solid line, 5  dashed line and 6  dashdotted line) and 79 calculations performed in the R1 nonMDPO hypothesis (d in the bottom figure, W_{T14} = 0.4 and P_{T14T14} equal to 0.2, 0.5 and 1 for 7  solid line, 8  dashed line and 9  dashdotted line); (a) in the bottom figure presents the theoretical basal reflections from pure 11 and 14 Å tobermorite (solid and dashed lines, respectively). 