Thermal expansivity of MgSiO₃ perovskite under high pressures up to 20 GPa

Abstract

Volume measurement of MgSiO3 perovskite was made in the temperature range from 25 to 500°C as a function of pressure up to 20 GPa by in situ x‐ray diffraction, using a DIA apparatus combined with synchrotron radiation. The measured thermal expansivity ranges from 1.8 to 2.5*10−5 /K and decreases only slightly with pressure. Our present results are in good agreement with the previous lower pressure (up to 11 GPa) data of Wang et al. [1994] and the higher pressure (36 GPa) data of Funamori and Yagi [1993], but contrast with the results using diamond anvil cell by Mao et al. [1991], particularly in a low pressure range.

Shock‐induced melting of MgSiO3 perovskite and implications for melts in Earth's lowermost mantle

“…[3] The thermal EOS of MgSiO 3 pv has been constrained by numerous static experiments and computational studies [Wang et al, 1994;Utsumi et al, 1995;Funamori et al, 1996;Saxena et al, 1999;Fiquet et al, 2000;Karki et al, 2001;Marton et al, 2001;Brodholt et al, 2002]. Previous dynamic pressure-density-internal energy (P-r-E) data for MgSiO 3 composition are compiled in Marsh [1980] and Simakov and Trunin [1973].…”

“…[2] The perovskite (pv) structure of (Mg, Fe)SiO 3 is considered to be the most abundant phase in the lower mantle, which makes its high-pressure, high-temperature behavior a matter of some interest. Of particular importance, given seismic ultra-low velocity zones (ULVZs) [Williams and Garnero, 1996] above the core-mantle boundary, are constraints on the phase relations and density contrasts among mantle solids, mantle melts, and the core that may explain the presence and stability of partial melting at the very base of the mantle [Montague and Kellogg, 2000;Namiki, 2003;Zhong and Hager, 2003].[3] The thermal EOS of MgSiO 3 pv has been constrained by numerous static experiments and computational studies [Wang et al, 1994;Utsumi et al, 1995;Funamori et al, 1996;Saxena et al, 1999;Fiquet et al, 2000;Karki et al, 2001;Marton et al, 2001;Brodholt et al, 2002]. Previous dynamic pressure-density-internal energy (P-r-E) data for MgSiO 3 composition are compiled in Marsh [1980] and Simakov and Trunin [1973].…”

Condensed-matter equation of states covering a wide region of pressure studied experimentally

“…To establish this point, we examine the experimental P -vs- V data for various solid-state condensed matter listed in Table 1, which include the elemental Sn, the transition-metals Au and Cu, the alkali halides LiF, NaF, NaCl and CsCl, ice VII, the oxides MgO and MgSiO 3 , the noble gases Ar, Kr and Xe, as well as molecular hydrogen H 2 D 2 . As representative examples of these analyses, we discuss the oxides MgO29303132333435 and MgSiO 3 363738394041. The isothermal P -vs- V relationships of these oxides have been extensively studied because they are the end members of (Mg,Fe)O4243 and (Mg,Fe)SiO 3 perovskite4244, which are the important components of the Earth’s lower mantle.…”

“…The isothermal P -vs- V relationships of these oxides have been extensively studied because they are the end members of (Mg,Fe)O4243 and (Mg,Fe)SiO 3 perovskite4244, which are the important components of the Earth’s lower mantle. The P -vs- V relationships for MgO29303132333435 were examined at room temperature in the 0–140 GPa range, and those for MgSiO 3 363738394041 at room temperature in the 0–300 GPa range. The P -vs- PV plots and the % error vs. P plots for MgO and MgSiO 3 are presented in Fig.…”

Earth Materials at High Pressure and Temperature: Recent Contributions from in situ Synchrotron X-Ray Diffraction

“…On the other hand, mineralogical studies formed only a minority of the early work done at the Photon Factory. Many [17,19] of them have been single-stage experiments on the phase relations of the olivine-wadsleyite-ringwoodite phases of the (Mg,Fe)2SiO4 system; perovskite phases such as CaSiO3 [18], neighborite [20], and (Mg,Fe)SiO3 [21][22][23][24][25] have also been investigated using both single-stage and two-stage arrangements. In the latter, one or more of the second-stage cubic anvils is constructed from sintered diamond to allow the transmission of the diffracted beam.…”