Ahn, JP Park, JK Kim, BK Huh, HY 2024-01-21T19:04:49Z 2024-01-21T19:04:49Z 2021-09-05 1997-01 1225-9438 https://pubs.kist.re.kr/handle/201004/144154 Tin oxide powders of nanometer size have been synthesized by a gas condensation method using helium or a mixture of oxygen and helium as the convection gas. Changes in the average size, morphology, and crystal phases were investigated during heat treatment at temperatures between 350 degrees C and 720 degrees C in the air. Spherical tin oxide powders of 15 nm in average diameter were synthesized in a helium atmosphere, which was composed of Sn, SnO, and Sn2O3 phases. After annealing at 720 degrees C, these multiphase particles transformed to a single SnO2 phase and became an irregular shape of about 50 nm in diameter. This rapid coarsening was attributed to fast mass transfer among particles. The spherical SnO2 powder of 7 nm in average diameter was directly synthesized using a gas mixture of oxygen and helium. Upon annealing up to 720 degrees C, morphological changes were barely observed in the powder synthesized using a convection atmosphere containing oxygen. English KOREAN INST METALS MATERIALS DIPHASIC XEROGELS NANOCRYSTALLINE Effect of convection gas on the synthesis of nanophase tin oxides during a gas condensation method Article 10.1007/BF03025961 1 METALS AND MATERIALS-KOREA, v.3, no.3, pp.188 - 192 METALS AND MATERIALS-KOREA 3 3 188 192 scie scopus 000072616700007 2-s2.0-0040747628 Materials Science, Multidisciplinary Metallurgy & Metallurgical Engineering Materials Science Metallurgy & Metallurgical Engineering Article DIPHASIC XEROGELS NANOCRYSTALLINE gas convection powder synthesis nanophase tin oxide gas condensation