Strain-induced phase and oxygen-vacancy stability in ionic interfaces from first-principles calculations...

Understanding interfacial chemistry is becoming crucial in materials design for
heterointerfaces. Using density functional theory, we elucidate the effect of strained
interfaces on phase and oxygen-vacancy stability for CeO2 | ZrO2, ThO2 | ZrO2 and CeO2
| ThO2 interfaces. The calculations show that ZrO2 transforms from cubic fluorite to the
orthorhombic columbite under tensile strain providing evidence of a previous
experimental speculation of an unrecognized ZrO2 phase. We also show that oxygen
vacancies could be preferably stabilized on either side of the interface by manipulating
strain. We predict that they are stable in tensile-strain, and unstable in compressivestrained
materials.