噴霧熱分解法によるBaTiO_3系微粉末の合成とその焼結性に及ぼすBa/Ti比とCuO添加の効果 : 合成・キャラクタリーゼーション

概要

論文の詳細を見る
BaTiO_3-basedfine powders, with Ba/Ti ratios ranging from 0.98 to 1.05, or comprising CuO up to 1 mol%, were synthesized by the spray pyrolysis technique. Starting solutions were prepared by dissolving Ba(NO_3), Ti[(CH_3)_2CHO]_4, and Cu(NO_3)_2・3H_2O in diluted nitric acid, and they were sprayed into the reaction chamber at 800℃ through a 2-fluid atomizer with pressurized oxygen gas. The obtained powder particles were hollow spheres 2 μm across on the average, which consisted of very small primary particles of around 10 nm. The powders were mostly BaTiO_3 with small amounts of residual compounds, which however, were removed completely by calcining at 620℃ for 1 h in an oxygen atmosphere. The calcination at 620℃ did not change the particle size. The Ba/Ti ratio of the powders affected the density and the microstructure of sintered bodies. An excess of BaO enhanced densification and gave a grain size discernibly larger than that of stoichiometric composition, whereas a sample containing excess TiO_2 component showed marked grain growth which caused the lower bulk density. When the Ba/Ti ratio was 1.03, the relative density of 95% was achieved at the lowest sintering temperature of 1250℃ without sintering aids. It should be noted that addition; of CuO to the powders with Ba/Ti ratio of 1.03 contributed to reducing the sintering temperature. Addition of 0.5 mol% CuO decreased the sintering temperature to 1060℃. The obtained sintered body showed a dielectric constant of 2300, dielectric loss of 0.9% at room temperature, and Curie temperature of around 130℃.
社団法人日本セラミックス協会の論文
1990-08-01

噴霧熱分解法によるBaTiO_3系微粉末の合成とその焼結性に及ぼすBa/Ti比とCuO添加の効果 : 合成・キャラクタリーゼーション

スポンサーリンク

概要

著者

関連論文

スポンサーリンク