An Alternative Route to Pentavalent Postperovskite

Area of Science:

• Materials Science
• Solid-State Chemistry
• High-Pressure Synthesis

Background:

• The CaIrO3-type structure is rare for pentavalent oxides.
• Post-perovskite phases are of significant interest due to their unique properties.

Purpose of the Study:

• To synthesize and characterize a new pentavalent CaIrO3-type oxide.
• To explore alternative synthetic routes to post-perovskite structures.

Main Methods:

• High-pressure and high-temperature synthesis.
• Utilizing two distinct precursor materials and conditions.

Main Results:

• Successfully synthesized post-perovskite NaOsO3 using two different routes.
• Identified a novel lower-pressure (6 GPa) synthesis pathway from Na2OsO4 and KSbO3-like phases.
• Demonstrated that perovskite intermediates are not always necessary for post-perovskite formation.

Conclusions:

• Post-perovskite structures can be accessed through diverse chemical pathways beyond traditional perovskite routes.
• The findings challenge existing generalized rules for post-perovskite synthesis.
• This work opens new avenues for discovering novel post-perovskite materials.