Characteristics of Nanosized Ni, NiCo-Y₂O₃ Powders Synthesized by a PVA Solution Route at Low Temperature.

Abstract

Nanosized Ni, NiCo-Y₂O₃ powders were successfully synthesized at low temperature via a simple polymer solution route. As an organic carrier, polyvinyl alcohol (PVA) afforded an atom-scale homogeneous precursor gel, which in turn gave fully crystallized nanosized Ni, NiCo-Y₂O₃ powder upon calcination at a low temperature under an Ar-4% H₂ atmosphere. The PVA content, calcination temperature, heating time, and reduction conditions affected the microstructure and crystallization behavior of the as-synthesized powders. The PVA content also influenced the synthesis behavior and microstructure of the final powder. The particle size increased with an increase in the calcination temperature and decrease in the PVA content. At a PVA-metal ion ratio of 4:1, the measured particle size was about 20 nm. The results of TEM mapping on the NiCo-Y (0.6 wt%) powders revealed a well-dispersed Y₂O₃ phase in the NiCo crystalline matrix.