TY - JOUR
T1 - A critical evaluation of pressure scale at high temperatures by in situ X-ray diffraction measurements
AU - Fei, Y.
AU - Li, J.
AU - Hirose, K.
AU - Minarik, W.
AU - Van Orman, J.
AU - Sanloup, C.
AU - van Westrenen, W.
AU - Komabayashi, T.
AU - Funakoshi, K.-I.
PY - 2004/6/15
Y1 - 2004/6/15
N2 - We conducted multi-anvil experiments at simultaneous high pressures and temperatures using multiple internal pressure standards including Au, Pt, MgO, W, Mo, Pd, and Ag. Extensive synchrotron X-ray diffraction data for Au, Pt, and MgO were collected at pressures up to 28 GPa and temperatures between 300 and 2173 K. We compare pressures calculated from different pressure scales and demonstrate large discrepancies in pressure determination using different pressure standards or different thermal equations of state for the same standard. The comparison allows us to quantitatively determine the differences in pressure using different pressure scales in the high P - T experiments. Using the MgO scale of [J. Geophys. Res. 106 (2001) 515] as a reference pressure scale, new Au and Pt scales are presented that are consistent with the MgO scale. We further examined the validity of the assumption of constant q value (volume dependence of the Grüneisen parameter in the Mie-Grüneisen relation) for the calculations of thermal pressures, and show that an expression of q as a function of temperature and pressure may be necessary to best fit the simultaneous high P - T data.
AB - We conducted multi-anvil experiments at simultaneous high pressures and temperatures using multiple internal pressure standards including Au, Pt, MgO, W, Mo, Pd, and Ag. Extensive synchrotron X-ray diffraction data for Au, Pt, and MgO were collected at pressures up to 28 GPa and temperatures between 300 and 2173 K. We compare pressures calculated from different pressure scales and demonstrate large discrepancies in pressure determination using different pressure standards or different thermal equations of state for the same standard. The comparison allows us to quantitatively determine the differences in pressure using different pressure scales in the high P - T experiments. Using the MgO scale of [J. Geophys. Res. 106 (2001) 515] as a reference pressure scale, new Au and Pt scales are presented that are consistent with the MgO scale. We further examined the validity of the assumption of constant q value (volume dependence of the Grüneisen parameter in the Mie-Grüneisen relation) for the calculations of thermal pressures, and show that an expression of q as a function of temperature and pressure may be necessary to best fit the simultaneous high P - T data.
UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-2442449112&partnerID=8YFLogxK
U2 - 10.1016/j.pepi.2003.09.018
DO - 10.1016/j.pepi.2003.09.018
M3 - Article
AN - SCOPUS:2442449112
SN - 0031-9201
VL - 143-144
SP - 515
EP - 526
JO - Physics of the Earth and Planetary Interiors
JF - Physics of the Earth and Planetary Interiors
ER -