Defects
In the most stable fluorite phase of ceria, it exhibits several defects depending on partial pressure of oxygen. The primary defects of concern are oxygen vacancies and small polarons (electrons localized on cerium cations) because these two are located in the "useful" range of ceria. In the case of oxygen defects, the increased diffusion rate of oxygen in the lattice causes increased catalytic activity as well as an increase in ionic conductivity, making ceria interesting as a fuel cell electrolyte in solid-oxide fuel cells.
Read more about this topic: Cerium(IV) Oxide
Famous quotes containing the word defects:
“The defects of the mind, like those of the face, grow worse with age.”
—François, Duc De La Rochefoucauld (1613–1680)
“A fool may be a dangerous customer, but the fact of his having such a vulnerable top-end turns danger into a first-rate sport; and whatever defects the old administration in Russia had, it must be conceded that it possessed one outstanding virtue—a lack of brains.”
—Vladimir Nabokov (1899–1977)
“The machine is impersonal, it takes the pride away from a piece of work, the individual merits and defects that go along with all work that is not done by a machine—which is to say, its little bit of humanity.”
—Friedrich Nietzsche (1844–1900)