SYNTHESS AND CHARACTERIZATION OF PURENANOCRYSTALLINE NCKELALUMNATE SPNEL POWDER

Synthesis of nanocrystalline nickel aluminate spinel (NiAlO4) by mechanical activation of a powder mixture containing Al and NiCOs with subsequent annealing was investigated. Simultaneous thermal analysis (STA), X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques were utilized to characterize the as-milled and annealed samples. Results showed that pure nanocrystalline spinel could be fabricated completely by 5h of mechanical activation with subsequent annealing at 1200 °C for 1 h with a crystallite size of about 22 nm. Further milling had no significant effects on structure or phase composition of spinel phase after subsequent annealing. The nanocrystalline spinel powder obtained after 20 h of milling and subsequent annealing at 1200 °C for 1 h had a crystallite size of about 27mm according to Williamson-Hall approach.

Keywords:

Nickel aluminate , nanostructure , mechanical activation , spinel , heat treatment