Thermal expansivity of lower mantle phases MgO and MgSiO3 perovskite at high pressure derived from vibrational spectroscopy

1996 ◽  
Vol 98 (1-2) ◽  
pp. 3-15 ◽  
Author(s):  
A. Chopelas
Keyword(s):  
High Pressure ◽  
Vibrational Spectroscopy ◽  
Lower Mantle ◽  
Thermal Expansivity ◽  
Mgsio3 Perovskite

High Pressure Elasticity of MgSiO3 Perovskite, MgO and SiO2

1997 ◽  
Vol 499 ◽  
Author(s):  
Bijaya B. Karki
Keyword(s):  
High Pressure ◽  
First Principles ◽  
Lower Mantle ◽  
Elastic Moduli ◽  
Local Density ◽  
Initial Pressure ◽  
Structural Transformations ◽  
Wave Velocities ◽  
Mgsio3 Perovskite ◽  
Shear Wave Velocities

ABSTRACTFull elastic constant tensors (cij) of three minerals namely, MgSiO3 perovskite, MgO and SiO2, are obtained as a function of pressure up to 140 GPa using first-principles computer simulations based on the local density and pseudopotential approximations. The zero pressure values and initial pressure dependence of athermal elastic constants derived from stress-strain relations are in excellent agreement with available experimental data. We find that elastic moduli, wave velocities and anisotropy of the minerals are strongly pressure dependent, particularly, in the vicinity of the structural transformations. In the view of the present experimental limitations at realistic conditions of the inner Earth, our results for high pressure elasticity are expected to be of substantial geophysical significance. Comparisons based on compressional and shear wave velocities support the prevailing hypothesis of Mg-rich silicate perovskite dominated composition for the lower mantle.

scholarly journals From Slater to Mott physics by epitaxially engineering electronic correlations in oxide interfaces

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Carla Lupo ◽  
Evan Sheridan ◽  
Edoardo Fertitta ◽  
David Dubbink ◽  
Chris J. Pickard ◽  
...  
Keyword(s):  
Phase Diagram ◽  
High Pressure ◽  
Charge Transfer ◽  
Lower Mantle ◽  
Random Structure ◽  
Titanium Oxides ◽  
Oxide Interfaces ◽  
Electronic Correlations ◽  
Epitaxial Strain ◽  
Magnetic Switching

AbstractUsing spin-assisted ab initio random structure searches, we explore an exhaustive quantum phase diagram of archetypal interfaced Mott insulators, i.e. lanthanum-iron and lanthanum-titanium oxides. In particular, we report that the charge transfer induced by the interfacial electronic reconstruction stabilises a high-spin ferrous Fe2+ state. We provide a pathway to control the strength of correlation in this electronic state by tuning the epitaxial strain, yielding a manifold of quantum electronic phases, i.e. Mott-Hubbard, charge transfer and Slater insulating states. Furthermore, we report that the electronic correlations are closely related to the structural oxygen octahedral rotations, whose control is able to stabilise the low-spin state of Fe2+ at low pressure previously observed only under the extreme high pressure conditions in the Earth’s lower mantle. Thus, we provide avenues for magnetic switching via THz radiations which have crucial implications for next generation of spintronics technologies.

High-pressure vibrational spectroscopy of sulfur dioxide

2005 ◽  
Vol 122 (17) ◽  
pp. 174511 ◽  
Author(s):  
Yang Song ◽  
Zhenxian Liu ◽  
Ho-kwang Mao ◽  
Russell J. Hemley ◽  
Dudley R. Herschbach
Keyword(s):  
High Pressure ◽  
Sulfur Dioxide ◽  
Vibrational Spectroscopy

High pressure effects on benzoic acid dimers: Vibrational spectroscopy

2014 ◽  
Vol 73 ◽  
pp. 138-143 ◽  
Author(s):  
Yuchuan Tao ◽  
Zbigniew A. Dreger ◽  
Yogendra M. Gupta
Keyword(s):  
High Pressure ◽  
Benzoic Acid ◽  
Vibrational Spectroscopy ◽  
Pressure Effects ◽  
High Pressure Effects

Partitioning of Fe within high-pressure silicate perovskite: Evidence for unusual geochemistry in the lower mantle

1987 ◽  
Vol 14 (3) ◽  
pp. 224-226 ◽  
Author(s):  
W. E. Jackson ◽  
E. Knittle ◽  
G. E. Brown ◽  
R. Jeanloz
Keyword(s):  
High Pressure ◽  
Lower Mantle

Thermal expansivity in the lower mantle

1992 ◽  
Vol 19 (19) ◽  
pp. 1983-1986 ◽  
Author(s):  
A. Chopelas ◽  
R. Boehler
Keyword(s):  
Lower Mantle ◽  
Thermal Expansivity
Sign in / Sign up

Export Citation Format

Share Document