Prospects for extending the battery life of hand-held devices such as cellphones and MP3 players have been boosted by the discovery that low-power memory chips made from "ferroelectric" materials could be made much denser than anyone thought. Until now, the bulkiness of ferroelectric memories has limited their use to applications in smart cards, which store only small amounts of data. Ferroelectricity is a phenomenon found in a class of materials knows as perovskites, in which ions in the material's crystal lattice are positioned in a way that separates positive and negative charges. In other words, they create an electric dipole within the perovskite crystal.
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