Properties of sol–gel derived Al2O3–15wt.% ZrO2 (3mol% Y2O3) nanopowders using two different precursors

Abstract An alumina–15 wt.% zirconia (3 mol% yttria) nanopowder was synthesized by sol–gel method using salt and alkoxide as precursors. Al(NO 3 ) 3 ·9H 2 O, ZrOCl 2 ·8H 2 O and Y(NO 3 ) 3 ·6H 2 O were used as salt precursors and Al(OC 4 H 9 ) 3 and Zr(OC 4 H 9 ) 4 were used as alkoxide precursors. The dried gels of two precursors were heat treated in the range of 450–1350 °C. The powders produced by alkoxide precursors calcined at 750 °C were in the range of 15–75 nm, while those prepared by salt precursors had the size in the range of 30–90 nm. The former powders had a higher surface area and smaller mean pore diameter compared with the later powder, i.e. 152 m 2 /g and 5.63 nm comparing with 121 m 2 /g and 9.79 nm, respectively. Therefore phase transformation in the former occurred in lower temperatures.