新铌酸盐Ba_5NdTi_3Nb_7O_(30)的合成与介电性能  

Synthesis and Dielectric Properties of a New Niobate Ba_5NdTi_3Nb_7O_(30)

作　　者：方亮[1] 张辉[1] 鄢俊兵[1] 杨卫明[1] 

机构地区：[1]武汉理工大学材料复合新技术国家重点实验室,武汉430070

出　　处：《无机化学学报》2002年第11期1131-1134,共4页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金资助项目(No.50002007);教育部重大项目及国际衍射数据中心(ICDD)Grant-in-Aid基金资助项目(No.01-40)。

摘　　要：The New Niobate Ba5NdTi3Nb7O30 was synthesized by solid state reaction at 1250℃ for 48h. The crystal structure and dielectric properties of Ba5NdTi3Nb7O30 were determined by X ray powder diffraction and dielectric measurements. The results show that Ba5NdTi3Nb7O30 belongs to ferroelectric phase of tetragonal tungsten bronze structure at room temperature with unit cell parameters: a=1.24424(4)nm, c=0.39476(2)nm, calculated density 5.719g·cm-3. Ba5NdTi3Nb7O30 belongs to relaxor ferroelectrics. The phase transition temperature (Tc) of Ba5NdTi3Nb7O30 from ferroelectric to paraelectric is found to shift toward higher temperature side at higher frequency, and Tc is 90℃ at 1kHz. At room temperature, the dielectric constant (εr) and dielectric loss of Ba5NdTi3Nb7O30 decrease with the increase of frequency, and Ba5NdTi3Nb7O30 ceramic have high dielectric constant 489 at 1kHz.The New Niobate Ba5NdTi3Nb7O30 was synthesized by solid state reaction at 1250degreesC for 48h.. The crystal structure and dielectric properties of Ba5NdTi3Nb7O30 were determined by X-ray powder diffraction and dielectric measurements. The results show that Ba5NdTi3Nb7O30 belongs to ferroelectric phase of tetragonal tungsten bronze structure at room temperature with unit cell parameters: a = 1.24424 (4) nm, c = 0.39476 (2) nm, calculated density 5.719g (.) cm(-3). Ba5NdTi3Nb7O30 belongs to relaxor ferroelectrics. The phase transition temperature (T-c) of Ba5NdTi3Nb7O30 from ferroelectric to paraelectric is found to shift toward higher temperature side at higher frequency, and T-c is 90degreesC at 1kHz. At room temperature, the dielectric constant (e,) and dielectric loss of Ba5NdTi3Nb7O30 decrease with the increase of frequency, and Ba5NdTi3Nb7O30 ceramic have high dielectric constant 489 at 1kHz.

关 键 词：铌酸盐 Ba5NdTi3Nb7O30 合成 介电性能 钨青铜结构 X射线衍射 铁电体 

分 类 号：TM225[一般工业技术—材料科学与工程]