Composition and conduction mechanism of the NASICON structure X-ray diffraction study on two crystals at different temperatures

Structure, Conductivity, and Ionic Motion in Na1+xZr2SixP3-xO12: A Simulation Study

“…In the case of rhombohedral Na 1+x Zr 2 Si x P 3-x O 12 , several authors have identified that there are prominently two crystallographically distinct sites Na(1) (the 6b positions) and Na(2) (the 18e positions) which the Na + ions can occupy. 2,11-14, 33 Cherkaoui et al in their NMR investigation on NaZr 2 (PO 4 ) 3 have suggested that apart from these two sites a third site (referred to as midNa site) of low occupancy exists in the pathway connecting the Na(1) and Na(2) sites and midway between the two. 34 Later single-crystal X-ray diffraction experiments on Na 3 Zr 2 Si 2 PO 12 by Boilot et al found that there is considerable Na + occupancy in the mid-Na site (36f positions), particularly near x ) 2 composition.…”

Alkali Metal Cation and Proton Conductors: Relationships between Composition, Crystal Structure, and Properties

“…Note that the same intermediate compositions exhibit maximum thermal expansion [24], so that the volume anomaly should enhance with temperature. At high temperatures, the monoclinic distortion vanishes due to a fast Na þ motion; in the diffraction data, this motion is described either by strongly anisotropic thermal parameters of Na(1) and Na(2), up to connection of their densities into a continuous basin [139], or by the appearance of an intermediate site, Na(3) (see Figure 7.15). At 350 C, the occupancies of Na(1), Na(2), and Na(3) are 0.4, 0.68, and 0.106, respectively [138].…”

Synthesis and characterization of a NaSICON series with general formula Na2.8Zr2−ySi1.8−4yP1.2+4yO12 (0⩽y⩽0.45)

“…In the ternary diagram delimited by the compositions NaZr 2 P 3 O 12 -Na 4 Zr 2 Si 3 O 12 -Na 4 Zr 1.25 P 3 O 12 [10], the studied samples are located on the line with general formula Na 2.8 Zr 2Ày Si 1.8À4y P 1.2+4y O 12 (0pyp0.45) as shown in Fig. 1.…”