Synthesis of gadolinium aluminate powder through citrate gel route

Nanocrystalline gadolinium aluminate (GdAlO(3)) powder was prepared through citrate gel route. The thermal decomposition behavior of gadolinium-aluminium-citrate-nitrate precursor powder was studied with the help of thermo gravimetric analysis combined with differential scanning calorimetry and mass spectroscopy. The phase evolution of the powder at different temperatures was characterized by high-temperature X-ray diffraction. The decomposition of the precursor powder in oxidizing atmosphere was found to be a three-step process: (i) evolution of water and ammonia; (ii) evolution of carbon dioxide, residual water, and ammonia; (iii) oxidation of residual carbon. Calcination of precursor powder at 800 degrees C under static air was found to result in GdAlO(3) phase. In the absence of oxidizing atmosphere the amorphous precursor powder only partially crystallized into GdAlO(3) phase at 1200 degrees C.