Materials Research Bulletin, Vol.48, No.2, 245-249, 2013
Cryogel synthesis and solid state reactivity of NdCaCoO4
The synthesis of NdCaCoO4 precursors was performed by coprecipitation followed by freeze drying. The thermal decomposition of the freeze dried product at T = 800 degrees C results in the formation of finely grained NdCaCoO4 while at higher temperatures the appearance of perovskite-like (Nd,Ca)CoO3-delta among reaction products is observed. Reaction of NdCaCoO4 with Al2O3 and ZrO2 at 900-1000 degrees C results in the complete disappearance of the initial phases while thermal processing of NdCaCoO4 mixtures with Gd-doped ceria or with MgO is not accompanied by the appearance of new reaction products. The doping of NdCaCoO4 with 2-10 mass.% of MgO by means of cryoimpregnation method causes a substantial decrease in NdCaCoO4 grain growth rate at 1000 degrees C and promoting its thermal stability. (c) 2012 Elsevier Ltd. All rights reserved.
Keywords:Inorganic compounds;Chemical synthesis;Electron microscopy;X-ray diffraction;Microstructure