Table 3. Detailed information for the crystal structure refinements of oP-Fe3O4 and Mg0.91 (2)Fe0.09 (2)SiO3 performed on laser-heated samples at ultra-high pressures.
Samples were measured at ambient temperature after a laser-heating procedure. For additional information on the crystal structures and refinement parameters we refer the reader to the CIFs in the supporting information.
| Crystal data | ||
| Chemical formula | Fe3O4 | Mg0.91 (2)Fe0.09 (2)SiO3 |
| Pressure (GPa) | ∼200 | ∼155 |
| M r | 231.5 | 103.3 |
| Crystal system, space group | Orthorhombic, Pnma | Orthorhombic, Pbnm |
| Temperature (K) | 293 | 293 |
| a, b, c (Å) | 7.932 (10), 2.5881 (13), 8.321 (3) | 4.194 (2), 4.525 (1), 6.1910 (1) |
| V (Å3) | 170.8 (2) | 117.49 (6) |
| Z | 4 | 4 |
| Radiation type | Synchrotron, λ = 0.483 Å | Synchrotron, λ = 0.483 Å |
| μ (mm−1) | 7.97 | 0.98 |
| Crystal size (µm3) | 1 × 2 × 1† | 2 × 2 × 2† |
| Data collection | ||
| Diffractometer | Single-circle (ω) diffractometer | |
| Absorption correction | Multi-scan, CrysAlis PRO 1.171.40.67a (Rigaku, 2019 ▸), empirical absorption correction using spherical harmonics, implemented in the SCALE3 ABSPACK scaling algorithm | |
| T min, T max | 0.559, 1 | 0.664, 1 |
| No. of measured, independent and observed [I > 2σ(I)] reflections | 195, 105, 88 | 106, 56, 53 |
| R int | 0.029 | 0.008 |
| (sin θ/λ)max (Å−1) | 0.643 | 0.607 |
| Refinement | ||
| R[F 2 > 2σ(F 2)], wR(F 2) | 0.071, 0.075 | 0.041, 0.114 |
| No. of reflections | 105 | 56 |
| No. of parameters | 22 | 13 |
| Δρmax, Δρmin (e Å−3) | 2.04, −1.8 | 0.51, −0.54 |
†
Approximate sizes based on X-ray diffraction 2D mapping.