| 학회 | 한국재료학회 |
| 학술대회 | 2009년 가을 (11/05 ~ 11/06, 포항공과대학교) |
| 권호 | 15권 2호 |
| 발표분야 | B. Nanomaterilas Technology(나노소재 기술) |
| 제목 | The effect of nano-sized starting materials and excess amount of Bi on the dielectric/piezoelectric properties of 0.94[(BixNa0.5)TiO3]-0.06[BaTiO3] lead free piezoelectric ceramics |
| 초록 | Abstract: In an approach to acclimate ourselves to recent ecological consciousness trend, a lead-free piezoelectric material, bismuth sodium titanate (abbreviated as BNT) based bismuth sodium barium titanate (abbreviated as BNT-BT), was considered as an environment-friendly alternative for a lead based piezoelectric system. Ceramic specimens of 0.94[(BixNa0.5)TiO3]-0.06[BaTiO3] (x = 0.500~0.515) compositions were prepared by a modified mixed oxide method. To increase the chemical homogeneity and reaction activity, high energy mechanical milling machine and pre-milled nano sized powder has been used. In this method (BixNa0.5)TiO3 (x=0.500~0.515) and BaTiO3 were prepared separately from pre-milled constituent materials at low calcination temperature and then separately prepared BNTX (X=1,2,3 and 4) and BT were mixed by high energy mechanical milling machine. Without further calcination step the mixed powders were pressed into disk shape and sintered at 1110°C. Microstructures, phase structures and electrical properties of the ceramic specimens were systematically investigated. Highly dense ceramic specimens with homogenous grains were prepared in spite of relatively low sintering temperature. Phase structures were not significantly influenced by the excess amount Bi. Large variation on the piezoelectric and dielectric properties was detected at relative high excess Bi amounts. When x≤ 0.505, the specimens exhibit insignificant variation in piezoelectric and dielectric constant though depolarization temperature is found to be decreased. Considerable amount of decrease in piezoelectric and dielectric properties are observed with higher excess of Bi amounts (x≥0.505). This research indicates the advantages of high energy mechanical milling and importance of proper maintenance of Bi stoichiometry. |
| 저자 | Neamul Hayet Khansur1, Soon-Chul Ur2, Man-Soon Yoon3 |
| 소속 | 1Dept. of Materials Sci. and Eng., 2Research center for Sustainable Eco-Devices and Materials (ReSEM), 3Chungju National Univ. |
| 키워드 | High energy mechanical milling; BNT-BT; Excess Bismuth |
