设计了特殊配方0.7BaO.0.3SrO·(1-y)TiO2·yNb2O5, 通过过量组成控制,制备了钙钛矿相和钨青铜相共存的复相陶瓷.用XRD和阻抗仪测试了相结构及介电常数.结果表明,在形成以钙钛矿为主相的体系中,Nb2O5过量6mol％以上时开始形成钨青铜相;在形成以钨青铜为主相的体系中,BaO和SrO过量11mol％以上时开始形成钙钛矿相.两相含量相当的体系中,钙钛矿相几乎不固溶Nb2O5,而钨青铜相固溶一定量TiO2.复相陶瓷的介电性能具有BST和SBN两相的特点.BSTN复相体系中钨青铜相的铁电/顺电转变温度随固溶TiO2量增加而降低,随钙钛矿相增加而升高,其最低转变温度约在200℃,比纯SBN相下降90℃.
Special compositions of Ba0.7Sr0.3·(1-y)TiO3·yNb2O5 were designed for preparing the BSTN system by the traditional ceramic method. The composite ceramics in which
the two phases of the perovskite (BST) and the tungsten bronze (SBN) coexist were successfully prepared by this composition controlled in the excessiveness of some components. XRD and LCR
were used to measure the structure and dielectric constants of the composite ceramics. It is found that, in the perovskite (BST) structured system of BSTN ceramics, the second phase SBN starts to
appear when the excessive content of Nb2O5 is up to about 6mol%. Similarly, in the tungsten bronze (SBN) structured system, the second phase of BST can also begin to form while the excessive
content of (BaO+SrO) is up to about 11mol%. However, both the perovskite and the tungsten bronze phases formed in a system exhibit the different minorities of Nb2O5 and TiO2 solved respectively
with changing the excessiveness. Especially in the case of the two phases being equivalent to each other in BSTN composite ceramics, Nb2O5 is hardly to be solved into the perovskite phase
due to shortage of Nb2O5 and excessiveness of TiO2 in composition. However, a few of TiO2 is easily to be solved in the tungsten bronze phase due to excessiveness of TiO2.There
is a dual characteristic shown by the perovskite phase and the tungsten bronze phase in temperature dependence curve of dielectric constant in the BSTN. The Curie temperature of the tungsten bronze
phase decreases with the increase in solubility of TiO2 in the phase structure. Conversely, the Curie temperature increases with increasing perovskite phase due to the primary effect of the tungsten
bronze phase being restricted by a lot of perovskite. The lowest transition temperature between ferroelectric and paraelectric phases in the BSTN is at about 200℃ and it is 90℃ lower than that
of the SBN without TiO2 solved in the present work.
参考文献
| [1] | Whatmore W R, Watton R. Ferroelectrics, 2000, 236(1-4): 259--279. [2] Owen R, Belcher J, Beratan H, et al. SPIE(Orlando), 1996, 2746: 101--112. [3] Lee Jae-Shin, Park Jae-Seok, Kim Jin-Sup, et al. Japanese Journal of Applied Physics, 1999, 38(5B): L574--L576. [4] Duran Cihangir, Trolier-McKinstry Susan, Messing Gary L. Journal of the American Ceramic Society, 2000, 83(9): 2203--2214. [5] Liu Shaobo, Liu Meidong, Jiang Sheng. Materials Science and Engineering B: Solid-State Materials for Advanced Technology, 2003, 99(1-3): 511--515. [6] Granzow T, Woike Th, Rammensee W, et al. physica status solidi (a), 2003, 197(3): R2--R4. [7] Xia H R, Xia H R, Chen H C, et al. physica status solidi (b), 1998, 210(1): 47--59. [8] Dietz G W, Schumacher M, Waser R, et al. J. Appl. Phys., 1997, 82: 2359. [9] Cheng Jian-Gong, Tang Jun, Chu Jun-Hao. Applied Physics Letters, 2000, 77(7): 1035--1037. [10] Kim Tae Song, Kim Chang Hee, Oh Myung Hwan. J. Appl. Phys., 1994, 76(7): 4316--4322. [11] Horikawa T, Mikami N, Ito H, et al. IEICE Trans.Electron, 1994, E77: 385--341. [12] 张福学, 孙慷. 压电学(下), 第一版. 北京: 国防工业出版社, 1984.189--190. [13] Glass A M. Appl. Phys. Let., 1968, 13: 147--149. [14] Banno H, Sugimoto N, Hayashi T. IEEE International Symposium on Applications of Ferroelectrics, 1996, 1: 523--526. [15] Yening Wang, Xiaobing Ren, Jianshe Liu, et al. Ferroelectrics, 1999, 231(1-4): 589--598. [16] Zhang NingXin, Li LongTu, Li BaoRang, et al. Materials Science and Engineering, 2002, B90(1-2): 185--190. [17] Sohn Jeong-Ho, Cho Jin-Woo, Lee Joon-Hyung, et al. Solid State Ionics, 1998, 108: 141--149. [18] Garcia S, Font R, Portelles J, et al. Journal of Electroceramics, 2001, 6(2): 101--108. [19] Amorin H , Portelles J, Guerrero F, et al. Journal of Electroceramics, 1999, 3(4): 371--375. [20] Guerrero Fidel, Amorin Harvey, Portelles Jorge, et al. Journal of Electroceramics, 1999, 3(4): 377--385. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%