title: Materials science. The hardest known oxide.
abstract: A material as hard as diamond or cubic boron nitride has yet to be identified, but here we report the discovery of a cotunnite-structured titanium oxide which represents the hardest oxide known. This is a new polymorph of titanium dioxide, where titanium is nine-coordinated to oxygen in the cotunnite (PbCl2) structure. The phase is synthesized at pressures above 60 gigapascals (GPa) and temperatures above 1,000 K and is one of the least compressible and hardest polycrystalline materials to be described.
authors: Institute of Earth Sciences, Uppsala University, S-752 36 Uppsala, Sweden. leonid.dubrovinsky@geo.uu.se
authors: L S
authors: LS
authors: Dubrovinsky
authors: N A
authors: NA
authors: Dubrovinskaia
authors: V
authors: V
authors: Swamy
authors: J
authors: J
authors: Muscat
authors: N M
authors: NM
authors: Harrison
authors: R
authors: R
authors: Ahuja
authors: B
authors: B
authors: Holm
authors: B
authors: B
authors: Johansson