Synthesis and Characterization of Sr₂Ce₂Ti₅O₁₆ in the System SrO‐CeO₂‐TiO₂

Abstract

The ternary system SrO-CeO,-TiO, was investigated using X-ray diffractometry. The formation of a new compound, Sr,Ce,Ti,O,,, was established, and its compatibilities with SrO, SrCeO,, and SrTiO, were studied. The results revealed the existence of a series of compounds Sr,-,,Ce,Ti,O,, and solid solutions Sr,+,Ce,Ti,+,O,,+,, (n I 6).

On the Formation of Americium-and Neptunium-Containing Titanates

“…However, the XRD results of the attempted reactions indicated that the solid solutions did not form, instead NpOj, Ti02, and a cubic phase were present. The latter is very likely a solid Solution within the series [16]. The inability to prepare Sr2An2Ti50,6 and their solid solutions with SraCejTijOje was consistent with similar behavior previously encountered in trying to prepare the Pu(IV) Compounds SrjPujTijOjft and Sr2Ce2-jPu^Ti50,6 [11].…”

“…While no Np(III) analog of SrLn2Ti40i2 was obtained, it was expected that Np(IV) would be stable in Compounds similar to Srfi.is^.Ces^TijOis [16], Thus, attempts were made to prepare the An(IV) (An = Am or Np) analogs of Sr2Ce2Ti50,6, a member of the series Sr6-,2^Ce6^Ti50,6 where x ~ 0.33. This series of Compounds is perovskite-like with XRD pattems and lattice parameters very similar to the series Sr4_^Ln2,/3Ti40,2 where x < 2.84 (cubic slightly distorted to tetragonal) [15].…”

“…The preparation of members of the solid Solution series Sr2Ce2-zNp,Ti50,6 was attempted by calcination of appropriate proportions of a mixture of SrTiOj, NpOz, and TiOj, equivalent to Sr2Np2Ti50,6, with SrzCeiTijOig prepared previously [16]. This final mixture was calcined in air at 1350°C for 50 to 90 hours.…”

“…Two series of perovskite-type solid solutions of composition Sr4_^Ln2,/3Ti40,2 (Ln = La-Nd), where the lanthanide is in the III oxidation State [15], and Srs-n^Ces^TisOiö, where cerium is in the IV oxidation State [16], have been identified earlier. By replacing the lanthanide in each system with an actinide of comparable size, such materials would offer the feasibility of concurrently immobilizing actinides and '"Sr. We have recenüy reported on the synthesis of SrPu2Ti40,2 (x = 3) and on unsuccessful attempts to prepare a plutonium analog of the Compound Sr2Ce2Ti50,6 0 = 0.33) [11], Here we report attempts and actual syntheses of analogous americium and neptunium Compounds.…”

Influence of secondary phases on phase and microwave dielectric properties of new Ca2Ce2Ti5O16 ceramics

“…Sr2Ce2Ti5O16 compound was reported by Bamberger et al [4] with pseudo cubic structure and its microwave dielectric properties i.e. r~113, high Qufo~8000 GHz and f~306 ppm/ o C were reported by Subodh et al [5].…”