FIG. 7 provides a schematic illustration of another crystal structure 700, which includes a first metal 705, oxygen atoms 710, and crystallographic defects 715. Here, crystallographic defects 715 may correspond to vacancy defects. The crystallographic defects 715 may be generated, for example, by introduction of one or more dopants 720 into the crystal structure 700. In some embodiments, the dopants 720 and crystallographic defects 715 may be introduced, for example, during the formation of the crystal structure, such as during an atomic layer deposition process. In some embodiments, the dopants 720 and crystallographic defects 715 may be introduced after the crystal structure 700 is formed, such as by an ion implantation or doping process. Useful dopants include, but are not limited to, alkali metal dopants, alkaline earth dopants, group 3 dopants, lanthanide dopants, titanium oxide dopants, hydrogen dopants, silver dopants, and/or lead dopants.
In embodiments, when an oxygen anion is added to the crystal structure 700 at a crystallographic defect 715, the electronic configuration of the crystal structure may change, such as due to the extra electrons carried by the oxygen anion. This configuration may create an unstable structure, and so the oxygen atoms may rearrange to accommodate the extra material added to the crystal structure and in this way allow oxygen anions to migrate through the crystal structure.
