单晶氧化镁在8吉帕斯卡压力和1600开尔文温度下的弹性。

Elasticity of single-crystal MgO to 8 gigapascals and 1600 kelvin.

作者信息

Chen G, Liebermann RC, Weidner DJ

机构信息

G. Chen, Center for High Pressure Research and Mineral Physics Institute, State University of New York (SUNY), Stony Brook, NY 11794, USA. R. C. Liebermann and D. J. Weidner, Center for High Pressure Research and Department of Geoscience.

出版信息

Science. 1998 Jun 19;280(5371):1913-6. doi: 10.1126/science.280.5371.1913.

DOI:10.1126/science.280.5371.1913

PMID:9632384

Abstract

The cross pressure (P) and temperature (T) dependence of the elastic moduli (Cij) of single-crystal samples of periclase (MgO) from acoustic wave travel times was measured with ultrasonic interferometry: partial differential2C11/ partial differentialP partial differentialT = (-1.3 +/- 0.4) x 10(-3) per kelvin; partial differential2C110/ partial differentialP partial differentialT = (1. 7 +/- 0.7) x 10(-3) per kelvin; and partial differential2C44/ partial differentialP partial differentialT = (-0.2 +/- 0.3) x 10(-3) per kelvin. The elastic anisotropy of MgO decreases with increasing pressure at ambient temperature, but then increases as temperature is increased at high pressure. An assumption of zero cross pressure and temperature derivatives for the elastic moduli underestimates the elastic anisotropy and overestimates the acoustic velocities of MgO at the extrapolated high-pressure and high-temperature conditions of Earth's mantle.

摘要

利用超声干涉测量法，通过声波传播时间测量了方镁石（MgO）单晶样品弹性模量（Cij）的交叉压力（P）和温度（T）依赖性：∂²C11/∂P∂T = (-1.3 ± 0.4) × 10⁻³ 每开尔文；∂²C110/∂P∂T = (1.7 ± 0.7) × 10⁻³ 每开尔文；以及∂²C44/∂P∂T = (-0.2 ± 0.3) × 10⁻³ 每开尔文。在常温下，MgO的弹性各向异性随压力增加而减小，但在高压下随温度升高而增大。在地球地幔的外推高温高压条件下，假设弹性模量的交叉压力和温度导数为零会低估MgO的弹性各向异性并高估其声速。