Figure 5: Powder XRD peak profiles of chibaite measured at a high-resolution setting.
From: New silica clathrate minerals that are isostructural with natural gas hydrates
Observed (black cross), calculated (red line) and difference (blue line) profiles at 2θ rages of (a) 12.38–13.38°, (b) 17.77–18.77°, (c) 26.7–27.8° and (d) 28.6–29.6°. The calculated profiles are the result of Le Bail fitting in the 2θ range from 6.5 to 31.1° using a cubic unit cell. The tick marks represent the calculated peak positions of the cubic (green) and tetragonal (pink) chibaite phases. The splitting of the cubic 004 and 260 reflections into the tetragonal 004/220 reflections and 116/332/240 reflections, respectively, are observed. Shifts of the peak positions from those of the ideal cubic phase and irregular variations of peak widths also show the presence of the tetragonal phase.
