Effects of La2O3 addition on the thermal stability of γ-Al2O3 gels

The effects of La2O3 additions up to 5 wt.% on the thermal stabilities of sol-gel derived alumina gels were studied. Observations were made on pore size, total pore area, phase changes at various sintering temperatures and times. XRD, Hg-porosimeter, DTA–TG techniques were employed. The addition of La2O3 to the sol-gel derived alumina gels raised the γ-Al2O3 to α-Al2O3 transformation temperature to 1200 °C. This significantly improves the thermal stabilities of alumina gels, that are employed in ceramic membranes.