Phase studies in the Cs–Sr–U–O system

The phase diagram in Cs–Sr–U–O quaternary system was analyzed at 900 °C in air atmosphere. A novel quaternary phase, Cs2Sr2U4O15, was identified in the system. It was obtained by heating the respective oxides at 900 °C in air. X-ray diffraction data of the compound was indexed in a monoclinic system with cell parameters, a = 0.9627(6) nm, b = 1.3742(8) nm, c = 0.7681(5) nm and β = 107.72(5)°, and was found to be isostructural with Rb2Sr2U4O15. A pseudo-ternary phase diagram of Cs2O–SrO–UO3 was drawn using a new quaternary compound and various phase fields were established by XRD analysis.