Concentration effect of Cs⁺ additive on the γ-Al₂O₃-to-α-Al₂O₃ phase transition

The effect of Cs⁺ additive on the γ-Al₂O₃-to-α-Al₂O₃ phase transition was investigated as a function of the Cs⁺ concentration by powder X-ray diffraction and specific surface area (S_A) measurements. The addition of Cs⁺ increasingly retarded the γ-to-α phase transition with increasing Cs⁺ concentration, reading a maximum at 5 mol% addition, at which the transition temperature was increasing by about 200 °C. This Cs⁺ concentration corresponds to an amount of cation which would almost fully cover the surface of the γ-Al₂O₃ grains.