@article{oai:soar-ir.repo.nii.ac.jp:00012450, author = {Odaka, Atsushi and Yamaguchi, Tomohiro and Fujita, Takayuki and Taruta, Seiichi and Kitajima, Kunio}, issue = {1}, journal = {POWDER TECHNOLOGY}, month = {Jul}, note = {Rare-earth (RE: Lu, Gd, Nd, 0.10 mol%)-doped alumina nanopowders were prepared by a new sol-gel route using polyhydroxoaluminum (PHA) and RECl(3) Solutions under alpha-alumina (similar to 75 nm) seeding. Among the rare-earth dopants studied, Lu yields the most suitable nanopowders for low-temperature densification. The 0.10 mol% Lu-doped nanopowders, which were obtained at a calcination temperature of 900 degrees C under 5 mass % alpha-alumina seeding, consisted of similar to 80-nm alpha-alumina particles and gamma-alumina nanoparticles. Using these Lu-doped alumina nanopowders, fully densified alumina ceramics with a uniform microstructure composed of fine grains with an average size of 0.61 mu m could be obtained at 1400 degrees C by pressureless sintering. Clearly, the Lu-doped nanopowders obtained here represent a viable option for fabricating dense, finer-grained alumina ceramics because an undoped sample with 5 mass% seeds gave a microstructure with an average grain size of 1.78 mu m at 1400 degrees C. (C) 2009 Elsevier B.V. All rights reserved., Article, POWDER TECHNOLOGY. 193(1):26-31 (2009)}, pages = {26--31}, title = {Densification of rare-earth (Lu, Gd, Nd)-doped alumina nanopowders obtained by a sol-gel route under seeding}, volume = {193}, year = {2009} }