Synthesis and characterization of sol-gel derived ZrO2 doped Al2O3 nanopowder

Al2O3-ZrO2 composite gel precursor powder containing 5-15 mol% ZrO2 was prepared by wet chemical route. The washed gel containing pseudoboehrnite and amorphous zirconia was characterized with respect to DTA/TG, XRD and IR spectroscopy. The DTA/TG result indicates three-stage decomposition for pseudoboehmite and single stage decomposition for amorphous zirconia. In the calcined powder phase evolution of Al2O3 follows the sequence pseudoboehmite -> bayerite boehmite -> gamma-Al2O3 -> theta-Al2O3 -> alpha-Al2O3, while that of ZrO2 follows amorphous ZrO2 -> t-ZrO2 (t + m)ZrO2. FTIR studies revealed that the number of M-OH and M-O bond increase on increasing mol% of ZrO2 due to a change in the cationic charge of the composite powder. TEM photograph of calcined powder showed both dispersed nano-size spherical particle as well as agglomerated particles. EPMA confirmed the near uniform distribution of zirconia particles in the alumina matrix. (c) 2006 Elsevier Ltd and Techna Group S.H. All rights reserved.