3. Equation of states (EOS)¶
Pressure is determined from the measured lattice constant (or unit-cell volume) of a standard material, using published equations of state. This is the standard method in X-ray diffraction experiments under high pressure. Select EOS at the top of the main window.
Workflow¶
- Enter the measurement temperature Temperature and the reference temperature T₀ (in K). Thermal equations of state use them; room-temperature scales ignore the difference.
- For each standard material, enter the ambient lattice constant a₀ (Å) and the measured lattice constant a (Å). For corundum and rhenium, the unit-cell volumes V₀ and V (ų) are entered instead.
- The pressure calculated with each published scale is displayed immediately (in GPa).
Available standards and scales¶
| Material | Scales |
|---|---|
| Gold | Jamieson (1982), Anderson (1989), Sim (2002), Tsuchiya (2003), Yokoo (2009), Fratanduono (2021) |
| Platinum | Jamieson (1982), Holmes (1989), Matsui (2009), Yokoo (2009), Fratanduono (2021) |
| NaCl B1 | Brown (1999), Matsui (2012) |
| NaCl B2 | Sata (2002) (Pt/Mg pressure references), Ueda+ (2008), Sakai+ (2011) BM/Vinet |
| Periclase (MgO) | Jackson (1998), Dewaele (2000), Aizawa (2006), Tange (2009) Vinet/BM |
| Corundum (Al₂O₃) | Dubrovinsky (1998) |
| Ar | Ross et al. (1986), Jephcoat (1998) |
| Re | Zha et al. (2004) and others |
| Mo | Zhao+ (2000), Huang+ (2016) MGD |
| Pb | Strässle+ (2014) |
Note
Different scales for the same material can disagree by several percent, particularly at multimegabar pressures. Report which scale was used when publishing results.