Figure 7: PXRD patterns for experimentally observed Ca-C phases.
From: Investigation of exotic stable calcium carbides using theory and experiment
(a) Pnma-Ca2C synthesized at 24 GPa (wRp=1.5%, Rp=0.9%). (b) C2/m-Ca2C3 synthesized at 17 GPa (wRp=2.0%, Rp=0.9%). Experimental data (points) are compared with full-profile refinements using the Le Bail method (blue lines), with differences (red lines). Simulated powder patterns using atomic positions derived from DFT-optimized structures are shown for intensity comparison (green lines). Positions of reflections of Ca2C (a) or Ca2C3 (b), Ca, Ne and a third carbide phase (see Supplementary Note 2) are indicated by black, green, blue and red tick marks, respectively.
