Preparations and characterisations of ceramics based on cesium titanate

AC Conductivity and Dielectric Properties of Lepidocrocite-type Alkali Titanate Tunable by Interlayer Cation and Intralayer Metal

“…Figure a is the Nyquist plot obtained from sintered Cs 0.7 Zn 0.35 Ti 1.65 O 4 , showing one semicircle from 200 to 350 °C. The presence of one semicircle is similar to the early work on lepidocrocite-type Cs 2 Ti 6 O 13 by Peres et al , indicating that bulk and grain boundary contributions cannot be separated. With increasing temperatures, the semicircles move to the high-frequency side and their diameters decrease, corresponding to the reduction in the real part of the impedance.…”

“…Examples include proton exchange, ,,, intercalation of bulky organic guest, − electrochemical intercalation, ,, chemical exfoliation, etc . However, there is a gap in our understanding of the thermally activated ion conduction in lepidocrocite-type alkali titanate , including its composition dependence. This might be attributed in part to the difficulty in specimen fabrication via conventional, high-temperature sintering, where the alkali loss could be expected. , The works by Ohashi , showed the conductivity up to 9.8 × 10 –6 S·cm –1 at −30 to 30 °C for polycrystalline A 0.68 ­Ti 1.83 ­O 4 · n H 2 O ( A = Cs, Na, Li, and H; n = 0–1.4).…”

Thermodynamic assessment of the hollandite high‐level radioactive waste form

“…Schmitz‐Dumont & Reckhard conducted liquidus measurements for the Cs 2 Ti 2 O 5 –TiO 2 system, reporting the formation of one intermediate stoichiometric compound, Cs 2 Ti 4 O 9 . Grey et al, however, did not observe the formation of Cs 2 Ti 4 O 9 but instead identified the compounds Cs 2 Ti 5 O 11 and Cs 2 Ti 6 O 13 , which were subsequently confirmed by Grey et al, Kwiatkowska et al, Bursill et al, Peres et al, and Kobyakov et al Thus, the Cs 2 Ti 4 O 9 compound, and by extension the liquidus data reported by Schmitz‐Dumont & Reckhard, was neglected while Cs 2 Ti 5 O 11 and Cs 2 Ti 6 O 13 were included in the assessment of the Cs 2 O–TiO 2 system. Grey et al were unable to experimentally determine the liquidus boundary in the analyzed 75‐100 mol% TiO 2 region of the Cs 2 O–TiO 2 system due to Cs volatilization, although phase transition temperatures were reported as follows: Cs 2 Ti 2 O 5 + Cs 2 Ti 5 O 11 → Cs 2 Ti 5 O 11 + melt = 1117 K, Cs 2 Ti 5 O 11 + melt → Cs 2 Ti 6 O 13 + melt = 1373 K, and Cs 2 Ti 6 O 13 + melt → TiO 2 + melt = 1405 K. Lu & Jin summarized TiO 2 melting temperatures measured in varied atmospheres, ultimately adopting the 2185 ± 10 K melting point measured for a near stoichiometric TiO 1.999 sample in a pure oxygen atmosphere.…”

“…Thus, BaO, Cs 2 O, and the additive oxides are dilute with respect to TiO 2 , which assures that two non-TiO 2 oxides are unlikely to interact whereas all will warrant a description of energetic interactions with TiO 2 . As such, Gibbs energies for the solid phases stable in the pseudo-binary systems of the oxides of substitutional elements with TiO 2 were incorporated into the database except for Al 2 31 Kwiatkowska et al, 32 Bursill et al, 33 Peres et al, 34 and Kobyakov et al 35 37,38 were used in the Cs 2 O-TiO 2 system assessment.…”

“…Grey et al 30 were unable to measure liquidus data due to high Cs volatility, and the liquidus data reported by Schmitz-Dumont & Reckhard 29 was neglected as the measurements indicated the formation of Cs 2 Ti 4 O 9 , which did not agree with other experimental studies of the C 2 O-TiO 2 system. [30][31][32][33][34][35] As such, estimation of the Cs 2 O-TiO 2 liquidus curve was required, which was based on the analogous K 2 O-TiO 2 phase diagram reported by Eriksson & Pelton. 46 Table S3).…”