Saxena SK, Dubrovinsky LS, Lazor P, Cerenius Y, Haggkvist P, Hanfland M, Hu J
S. K. Saxena, L. S. Dubrovinsky, P. Lazor, Y. Cerenius, P. Haggkvist, Theoretical Geochemistry, Institute of Earth Sciences, Uppsala University, S-752 36 Uppsala, Sweden. M. Hanfland, European Synchrotron Radiation Facility, Boite Postale 220, Avenue des Martyrs, 38043 Grenoble Cedex, France. J. Hu, Center for High Pressure Research, Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC, USA.
Science. 1996 Nov 22;274(5291):1357-9. doi: 10.1126/science.274.5291.1357.
Available thermodynamic data and seismic models favor perovskite (MgSiO3) as the stable phase in the mantle. MgSiO3 was heated at temperatures from 1900 to 3200 kelvin with a Nd-YAG laser in diamond-anvil cells to study the phase relations at pressures from 45 to 100 gigapascals. The quenched products were studied with synchrotron x-ray radiation. The results show that MgSiO3 broke down to a mixture of MgO (periclase) and SiO2 (stishovite or an unquenchable polymorph) at pressures from 58 to 85 gigapascals. These results imply that perovskite may not be stable in the lower mantle and that it might be necessary to reconsider the compositional and density models of the mantle.
现有的热力学数据和地震模型表明，钙钛矿（MgSiO₃）是地幔中的稳定相。在金刚石对顶砧槽中用钕钇铝石榴石激光将MgSiO₃在1900至3200开尔文的温度下加热，以研究45至100吉帕斯卡压力下的相关系。用同步加速器X射线辐射研究淬火产物。结果表明，在58至85吉帕斯卡的压力下，MgSiO₃分解为MgO（方镁石）和SiO₂（斯石英或一种不可淬火的多晶型物）的混合物。这些结果意味着钙钛矿在下地幔中可能不稳定，可能有必要重新考虑地幔的成分和密度模型。
