Pressure derivatives of the elastic constants of α-iron to 10 kbs

The effect of silicon impurities on the phase diagram of iron and possible implications for the Earth's core structure

“…The parameters for pure iron [19][20][21][22] persists for about 20 GPa [4]. As can be seen in the figure, we calculate that 7.9% Si will increase the pressure of the pseudo-univariant transition by ~16 GPa, a value that falls within the experimental solid solution range.…”

Inelastic x-ray scattering at ultrahigh pressures

“…This opens tremendous opportunities for complete characterization and tuning phonon dynamics over a large range of density. [87] and solid [49] squares, ultrasonic data; circles, RXD data with Au stress calibration [49]; small circles, RXD extrapolation based on constant K/G [49]; diamonds, present NRIXS results; solid curves, curve-fitting through the ultrasonic and the NRIXS data; dotted curve, calculated from the slope at the gamma point of the present ab-initio theoretical phonon dispersion curves; dashed curve, ab-initio calculations of Steinle-Neumann et al [88]. The vertical line at 13 GPa separates bee Fe and high-pressure hcp Fe.…”

High‐temperature viscoelastic relaxation in iron and its implications for the shear modulus and attenuation of the Earth's inner core

“…Pressure and temperature will often have opposing effects on A or GR/GHs, but this is not so for bcc-Fe, where through the disparity between the pressure derivatives of c44 and c' (2.6 and 1.1, respectively [Guinan and Beshers, 1968 The present study has documented marked dissipation and modulus dispersion associated with viscoelastic relaxation in both the bcc and fcc polymorphs of iron tested at seismic frequencies and homologous temperatures reaching 0.6 and almost 0.9 for the bcc and fcc phases, respectively. Both anelastic (recoverable) and viscous (irrecoverable) processes contribute to the dominant high-temperature dissipation background.…”