| Nanocrystalline La0.84Sr0.16MnO3 and NiO-YSZ by
Combustion of Metal Nitrate-Citric Acid/Glycine Gel
– Phase Evolution and Powder Characteristics |
M. B. Kakade,* K. Bhattacharyya1, R. Tewari2, R. J. Kshirsagar3, A. K. Tyagi1,
S. Ramanathan, G. P. Kothiyal and D. Das1
pages 182-190
DOI : 10.1080/0371750X.2013/851620 |
| Abstract |
| Phase evolution behaviour of lanthanum strontium manganite (LSM) and nickel oxide-yttria stabilized zirconia
(NiO-YSZ) composite from the respective oven dried fuel – metal nitrate gels (citrate-metal nitrate for LSM and
glycine-metal nitrate for NiO-YSZ) was studied using TG-DTA, XRD and FTIR. The TG-DTA revealed sharp exotherms
around 200o and 221oC attributed to the setting in of combustion of gels of LSM and NiO-YSZ respectively. The XRD
results indicated formation of nanocrystalline LSM and NiO-YSZ phases above 200o and 221oC respectively. The
FTIR spectra of LSM and NiO-YSZ gels heated above 200o and 221oC exhibited characteristic absorption bands
corresponding to metal-oxygen vibrations in LSM and NiO-YSZ indicating formation of the respective compounds.
However, chemical and phase pure LSM and NiO formed above 700oC indicate the minimum calcination temperature
to be used in the processing. The role of calcination treatment on powder characteristics in the temperature range
of 700o to 1350oC was studied. With increasing calcination temperature of the as-formed powders, the characteristics
such as crystallite size, median particle size (D50), green density of the compacts increased while specific surface
area decreased. Typical sintering studies at 1400o and 1450oC revealed that sinterability and per cent linear shrinkage
decreased with increasing calcination temperature. However, the required amount of porosity for SOFC application
could be obtained with incorporation of a pore former in case of LSM and varying the sintering time in case of NiOYSZ
composite. |
| Full text : Subscribe to Download Full Text |
| [Go Back] |
|
