Fig. 2: X-ray diffraction.
From: Pressure tuning of competing interactions on a honeycomb lattice
a Pressure-dependent diffraction patterns at 293 K (black) and 83 K (red). The *, +, and . symbols indicate, respectively, the Re peaks (gasket), Au peaks (manometer), and boron carbide seat. Red vertical bars in the bottom panel indicate calculated Bragg peak intensities at 1.9 GPa (293 K) and 2.7 GPa (83 K). b Monoclinic unit cell parameters, angle β, and volume plotted as a function of pressure. The P-V data are fitted (solid lines) using both second-order Vinet and second-order Birch–Murnaghan equations of state, rendering comparable values for the bulk modulus (B0) and ambient pressure volume (V0). c The bifurcation of the 9.5° Bragg peak at Pc = 6.6 GPa indicates a dimerization transition (see also Fig. S2). d The linear and quadratic dependence of K and J on ∠Rh-O-Rh are reproduced from ref. 16. Dashed lines indicate the average bond angle at different pressures.
