Electron Diffraction and 47,49 Ti and 17 O NMR Studies of Natural and Synthetic Brookite

Brookite, TiO 2, synthesized by hydrothermal processing of a titanium oxide gel was shown by powder X-ray and single-crystal electron diffraction to consist of very well ordered single crystals. The titanium coupling constant determined from 47,49 Ti NMR spectroscopy is intermediate between the coupling constants for anatase and rutile. 17 O NMR spectroscopy locates the two crystallographically inequivalent oxygen atoms in brookite. Electron diffraction and microscopy and Ti NMR show that a comparison sample of naturally occurring brookite has many more defects.