Synthesis and phase structure of (Cs0.8−xBa0.4+x)(Al1.6+ x3+Ti6.4− x4+)O16 ceramics using sol-spray pyrolysis route for immobilizing radioactive cesium.

In this paper, a sol-spray pyrolysis route was employed to fabricate (Cs, Ba)-hollandite ceramic waste forms. The high-phase purity (Cs_0.8−xBa_0.4+x)(Al_1.6+xTi_6.4−x)O₁₆ (0 ≤ x ≤ 0.4) ceramics were synthesized at 1050 °C using the produced powders by sol-spray pyrolysis. The results show that all samples show tetragonal hollandite with rod morphology. Additionally, the sintered (Cs, Ba)-hollandite ceramics exhibit a good chemical durability. The normalized release rates of Cs and Ba were < 10⁻² g m⁻² d⁻¹ after 14 days. These results indicate that hollandite ceramics are promising candidate for immobilizing radioactive cesium. [ABSTRACT FROM AUTHOR]