Related Experiment Video
Updated: Jul 25, 2026

Influence of Hybrid Perovskite Fabrication Methods on Film Formation, Electronic Structure, and Solar Cell Performance
Published on: February 27, 2017
MgSiO3 postperovskite at D'' conditions.
Renata M Wentzcovitch1, Taku Tsuchiya, Jun Tsuchiya
1Department of Chemical Engineering and Materials Science, Minnesota Supercomputing Institute for Digital Technology and Advanced Computation, University of Minnesota, 421 Washington Avenue Southeast, Minneapolis, MN 55455, USA. wentzcov@cems.umn.edu
The postperovskite phase transition in MgSiO3 provides a model for Earth's D'' layer. This study confirms its presence and explains seismic anomalies in the lowermost mantle.
Area of Science:
- Geophysics
- Mineral Physics
- Earth Science
Background:
- The D'' discontinuity in Earth's lower mantle is a complex region.
- The postperovskite phase transition in MgSiO3 is a key phenomenon occurring under D'' conditions.
Purpose of the Study:
- To investigate the thermoelastic properties of Cmcm postperovskite.
- To provide evidence for the presence of postperovskite in the lowermost mantle.
- To explain observed geophysical anomalies in the D'' region.
Main Methods:
- Experimental determination of thermoelastic properties of Cmcm postperovskite.
- Analysis of seismic velocity jumps and anomalies in the D'' region.
Main Results:
- Observed jumps in shear and longitudinal velocities consistent with seismic data.
- Anticorrelation between shear and bulk velocity anomalies detected.
- Increased shear modulus across the postperovskite phase transition.
Conclusions:
- The postperovskite phase is present in the Earth's lowermost mantle.
- The phase transition explains seismic velocity variations and anomalies in the D'' region.
- The study reconciles discrepancies between theoretical and seismological shear modulus values.
More Related Videos
08:55Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
04:09Demonstrating the Simplicity and In Situ Temperature Monitoring of the Mechanochemical Synthesis of Metal Chalcogenides Suitable for Thermoelectrics
Published on: August 30, 2024
Related Concept Videos
Molecular and Ionic Solids
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Common Ion Effect
Qualitative Analysis
For instance, group IV...
Valence Bond Theory
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.