Doping in the Valley of Hydrogen Solubility: A Route to Designing Hydrogen-Resistant Zirconium Alloys

Hydrogen embrittlement of metallic alloys is critical to the aging and failure of components in power plants and infrastructure. Embrittlement begins with hydrogen penetrating the protective oxide film that naturally grows on a surface in air. The authors apply concepts from semiconductor defect physics and catalysis to develop materials engineering strategies for thwarting hydrogen uptake. For ZrO₂ film on a Zr alloy, a model system that is important for materials in nuclear reactors, they demonstrate that one can use doping to tune the chemical potential of electrons in ZrO₂ either to minimize the solubility of hydrogen, or to facilitate its evolution as H₂ gas from the surface.