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.
- Publication:
-
Nature
- Pub Date:
- April 2001
- DOI:
- 10.1038/35070650
- Bibcode:
- 2001Natur.410..653D