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)
“There’s terrific merit in having no sense of humour, no sense of irony, practically no sense of anything at all. If you’re born with these so-called defects you have a very good chance of getting to the top.”
—Peter Cook (b. 1937)
“All conservatives are such from personal defects. They have been effeminated by position or nature, born halt and blind, through luxury of their parents, and can only, like invalids, act on the defensive. But strong natures, backwoodsmen, New Hampshire giants, Napoleons, Burkes, Broughams, Websters, Kossuths, are inevitable patriots, until their life ebbs, and their defects and gout, palsy and money, warp them.”
—Ralph Waldo Emerson (1803–1882)