Unconventional stable stoichiometry of vanadium peroxide

Area of Science:

• Materials Science
• Solid-State Chemistry
• Computational Materials Science

Background:

• Peroxides are intriguing due to their electronic properties and applications.
• Known transition metal peroxides are limited, hindering diverse applications.
• Vanadium-oxygen (V-O) systems offer potential for novel peroxide discovery.

Purpose of the Study:

• To explore and stabilize new peroxide stoichiometries in the vanadium-oxygen system.
• To investigate the electronic properties and stability of novel vanadium peroxides under high pressure.
• To identify new superconducting materials within the V-O system.

Main Methods:

• First-principles calculations were employed to predict material stability.
• Swarm-intelligence structure search identified potential new stoichiometries.
• High-pressure conditions were simulated to analyze material behavior.

Main Results:

• Two new thermodynamically stable vanadium peroxide stoichiometries, V2O and VO4, were predicted at megabar pressures.
• VO4 exhibits the highest oxygen content among known peroxides.
• V2O demonstrates superconductivity, marking the first instance in the V-O system.
• The electronic band gap of VO4 increases with pressure due to reduced O-O bond length.

Conclusions:

• The study successfully identified novel vanadium peroxide compounds, expanding the family of known peroxides.
• The findings reveal unique electronic properties of vanadium oxides under high pressure, including pressure-induced band gap increase and superconductivity.
• This research provides a foundation for further exploration of transition metal peroxides and their high-pressure behavior.