Electron microscopic studies of the fibrous cesium titanate Cs2Ti5O11 reveal characteristic features not readily apparent using standard methods of phase analysis (optical microscopy, X-ray diffraction). Its fibrous needle-like laths give characteristic diffuse scattering, complicating the indexing of electron diffraction patterns. The hydrated form Cs2Ti5O11 · (1 + x)H2O (0.5 < x < 1) is typically grossly distorted, resembling pyrolytic graphite. Cs2Ti5O11 is unstable when stored under ambient conditions at room temperature for ∼1 year when disproportionation into Cs2Ti4O9 and Cs2Ti6O11 · nH2O occurs. The structure of Cs2Ti5O11 and intergrowth defects in the unstable forms have been studied by high-resolution electron microscopy. It is evident that these phases would be undesirable in titanate ceramics such as SYNROC, which are designed for immobilization of radioactive 137Cs.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry