PREPARATION AND THERMAL-STABILITY OF LA2O3-AL2O3 AEROGELS FROM CHEMICALLY-MODIFIED AL-ALKOXIDE

La-doped Al2O3 aerogels (containing 0.5-10 mol% La2O3) were prepared u sing Al-alkoxide chemically modified with ethyl acetoacetate. The spec ific surface area of non-doped Al2O3 aerogels heal-treated at 1000 to 1200 degrees C was greatly increased by doping a small amount of La2O3 . X-Ray diffraction measurements showed that the crystalline phase of La-doped Al2O3 aerogels containing 1 mol% La2O3 heat-treated at 1200 d egrees C for 2 h was theta-Al2O3, while that of non-doped Al2O3 aeroge ls was alpha-Al2O3. The La2O3-Al2O3 aerogels heat-treated at 1000-1200 degrees C showed the largest specific surface area at the composition of 1 mol% La2O3 with the presence of the theta-Al2O3 phase.