Polymerized Complex Route to Synthesis of Pure Y 2 Ti 2 O 7 at 750°C Using Yttrium‐Titanium Mixed‐Metal Citric Acid Complex

A polymerized complex technique was used to prepare high‐purity pyrochlore Y 2 Ti 2 O 7 powders at 750°C. Heating of a mixed solution of citric acid (CA), ethylene glycol (EG), and yttrium and titanium ions, with a molar ratio of CA:EG:Y:Ti = 5:20:1:1, at 130°C produced a yellowish transparent polymeric gel without any precipitation; this material was used subsequently as a precursor for Y 2 Ti 2 O 7 . Based on the results of 13 C‐NMR spectroscopy, it was suggested that a mixed‐metal (Y,Ti)‐CA 3 chelate complex formed in a starting CA/EG solution. The formation of pure pyrochlore Y 2 Ti 2 O 7 occurred when the precursor was heat‐treated in a furnace set at 750°C in static air for 4 h.