(Mg,Fe)SiO3-perovskite stability under lower mantle conditions

Area of Science:

• Geophysics
• Mineral Physics

Background:

• The lower mantle is primarily composed of (Mg,Fe)SiO3-perovskite.
• Understanding the stability of this mineral is crucial for geodynamic models.

Purpose of the Study:

• To investigate the stability of (Mg,Fe)SiO3-perovskite at high pressures and temperatures.
• To determine the decomposition behavior of perovskite under lower mantle conditions.

Main Methods:

• Experiments were conducted using a diamond anvil cell.
• Pressures up to 100 gigapascals and temperatures up to 3000 kelvin were applied.
• Raman spectroscopy and fluorescence measurements were used for analysis.

Main Results:

• (Mg,Fe)SiO3-perovskite remained stable up to 100 gigapascals and 3000 kelvin.
• Perovskite formed from component oxides (Mg, Fe)O and SiO2 under high pressure.
• Raman spectra confirmed perovskite as a single phase, and fluorescence data indicated no MgO presence.

Conclusions:

• (Mg,Fe)SiO3-perovskite is stable under simulated lower mantle conditions.
• The mineral does not decompose into its constituent oxides at extreme pressures and temperatures.