Acceptor doping in the proton conductor SrZrO₃.

Area of Science:

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

Background:

• Perovskite zirconates like SrZrO3 are investigated for proton conductivity.
• Doping with trivalent cations at the Zr site can enhance proton solubility and conductivity.

Purpose of the Study:

• To investigate the effects of Scandium (Sc) and Yttrium (Y) dopants on SrZrO3.
• To understand the defect chemistry and proton interactions in doped SrZrO3.

Main Methods:

• First-principles calculations
• Hybrid density-functional theory (DFT)
• Analysis of defect formation and charge transition levels

Main Results:

• Sc and Y form deep acceptor levels when substituting Zr (ScZr, YZr).
• Self-compensation occurs when Sc and Y substitute Sr (ScSr, YSr), negatively impacting conductivity.
• Proton binding energies indicate trapping at impurity sites limits transport.

Conclusions:

• Sc and Y doping in SrZrO3 create acceptor states but also self-compensating donors.
• Proton transport is limited by trapping at Sc and Y impurity sites.
• Understanding dopant behavior is crucial for optimizing proton conductivity in perovskite zirconates.