Extended Data Fig. 2: X-ray diffraction patterns from CaSiO3 perovskite.
From: Seismic velocities of CaSiO3 perovskite can explain LLSVPs in Earth’s lower mantle
Shown are stacked diffraction patterns of CaSiO3 perovskite; each panel shows data at 300 K, 373 K and 473 K (see key in a). a, Full patterns; b, c, patterns limited in the 2θ range to allow indication of weak superlattice peaks. The positions of the diffraction peaks from the Ca-Pv sample, MgO, NaCl and Au are indicated by markers—other small peaks are from boron epoxy and/or furnace components. Cubic Ca-Pv peaks are labelled with indices, hkl, in bold. The diffraction patterns reveal the appearance of small superlattice reflections at T = 373 K and 300 K at 2θ values of about 6.1°, 8.05°, 12.1° and 13.2° (we note there is believed to be an additional superlattice reflection obscured at 2θ = 10.5°) labelled with hkl indexed on the tetragonal (I4/mcm) unit cell and marked with gold stars.
