Study on thermolysis process of a new hydrated and protonated perovskite-like oxides H2K0.5Bi2.5Ti4O13•yH2O

A protonated form of the n = 4 layered bismuth containing perovskite-like titanate K2.5Bi2.5Ti4O13 belonging to Ruddlesden-Popper phases was prepared via ion exchange reaction of interlayer K+ with protons. Its composition was investigated by TG ICP and EDX analysis was found to be H2K0.5Bi2.5Ti4O13 center dot H2O. The thermal behavior of the obtained phase was investigated by STA coupled with mass-spectrometry, the structural changes, happening with the sample during heating, were examined by XRD. It was shown that the as-prepared hydrated phase undergoes two-stage dehydration at low temperatures (up to 160 degrees C). The further heating leads to the gradual decomposition and crystallization of new phases, notably Bi2Ti2O7, Bi4Ti3O12 and Bi2Ti4O11. The morphology of the as-prepared sample and samples after heat treatment was examined using SEM.