Identifying characteristics of the fibrous cesium titanate Cs 2Ti 5O 11

• Published in: Journal of solid state chemistry Vol. 69; no. 2; pp. 360 - 368
• Main Authors: Bursill, L.A., Smith, David J., Kwiatkowska, Jadwiga
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 1987
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/0022-4596(87)90094-6

Electron microscopic studies of the fibrous cesium titanate Cs 2Ti 5O 11 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 Cs 2Ti 5O 11 · (1 + x)H 2O (0.5 < x < 1) is typically grossly distorted, resembling pyrolytic graphite. Cs 2Ti 5O 11 is unstable when stored under ambient conditions at room temperature for ∼1 year when disproportionation into Cs 2Ti 4O 9 and Cs 2Ti 6O 11 · nH 2O occurs. The structure of Cs 2Ti 5O 11 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 137C s.