Ion-exchange reactions in the structure of perovskite-like layered oxides: I. Protonation of NaNdTiO4 complex oxide

The behavior of perovskite-like NaNdTiO 4 complex oxide in acid aqueous solutions was studied. By the X-ray and thermogravimetry analyses the instability of NaNdTiO 4 in aqueous solutions was found, which is determined by the sodium cation exchange for protons and by water molecules intercalation into the interlayer space of the crystal structure. The proton-containing layered oxides HNdTiO 4 and H x Na 1− x NdTiO 4 · y H 2 O were obtained (1 < x < 0.64, 0 < y < 0.47). The structure of the H 0.73 Na 0.27 NdTiO 4 ·0.3H 2 O compound was refined.