摘要
用传统的烧结法,经850-950℃预烧和1050-1090℃烧结,制备了CaCu3Ti4O12 巨介电常数陶瓷,通过X射线衍射(XRD)、扫描电镜(SEM)分别对体系进行了结晶性能和形 貌测试,用阻抗分析仪对试样在50-300K温区范围内介电性能进行了测试.研究结果表明, CaCu3Ti4O12结晶完整性、晶界及缺陷对其巨介电常数的大小、出现低介电常数向高介电常数 转变时对应温度的高低有直接的影响.在950℃预烧和1090℃下烧结的样品要比880℃预烧 和1050℃下烧结样品出现极化子松弛时对应的温度下降约70K,介电常数相对提高约300％, 在较大的温区范围具有高的介电常数.材料的结晶越完整,由低到高介电常数的转变速度越 快.
CaCu3Ti4O12 ceramics with giant dielectric constant were prepared by the traditional ceramic method, in which the oxide powders were mixed and pre-sintered at 850 similar to 950 degrees C, and then sintered at 1050 similar to 1090 degrees C, respectively. XRD, SEM and LCR were used to measure the phase structure, the morphology and dielectric properties of the ceramics. The results show that the dielectric constant and the temperature at which the low dielectric constant typically transforms to special high are seriously controlled by the perfection and the defects of grain boundaries of the crystalline. The relaxation temperature of the dipole in the sample pre-sintered at 950 degrees C and sintered at 1090 degrees C is 70K lower than that of the dipole in the sample pre-sintered at 880 degrees C and sintered at 1050 degrees C, and the dielectric constant is 300% enhanced, and simultaneously remains giant in a relative wide temperature range. The better the crystallinity of the ceramic, the faster the transation of the dielectric constant from low to high.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第2期484-488,共5页
Journal of Inorganic Materials
基金
国家自然科学基金(50372057
50332030)教育部高等学校博士学科点专项科研基金(20020335017)教育部留学回国基金
