Synthesis and thermal stability studies of a series of metastable Dion–Jacobson double-layered neodymium-niobate perovskites

• A series of new layered neodymium containing perovskites were synthesized by ion exchange.
• Products were studied by variable temperature X-ray diffraction and thermal analysis.
• Most of the series are metastable showing exothermic transitions on decomposition.
• The Nd compounds are less stable due to the smaller size of the Nd relative to La.

The Dion–Jacobson double-layered perovskite, RbNdNb2O7, is used as a precursor to synthesize the series ANdNb2O7 (A=H, Li, Na, K, NH4, Ag), and (MCl)NdNb2O7 (M=Mn, Fe, Cu) through ion-exchange reactions ≤400 °C. Thermal stability studies indicated that most of these compounds are metastable. A combination of X-ray powder diffraction and differential thermal analysis were used to determine various low temperature decomposition pathways; these pathways were very dependent on the interlayer species. Overall the ANdNb2O7 series was found to be less stable than the corresponding lanthanides, ALaNb2O7.

A new series of topochemically-prepared metastable neodymium-containing layered perovskites are studied.Figure optionsDownload as PowerPoint slide