铋层状化合物Sr_(0.3)Ba_(0.7)Bi_(4-x)La_xTi_4O_(15)陶瓷材料的介电性能  

DIELECTRIC PROPERTIES OF BISMUTH-LAYERED COMPOUND Sr_(0.3)Ba_(0.7)Bi_(4-x)La_xTi_4O_(15 )

作　　者：黄平[1] 徐廷献[1] 孙清池[1] 

机构地区：[1]天津大学材料学院先进陶瓷与加工技术教育部重点实验室,天津300072

出　　处：《硅酸盐学报》2004年第7期808-811,共4页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金重大资助项目(59995520);Nippondegree.SheetGlassFoundationforMaterialsScienceandEngineering资助项目(30105544)。

摘　　要：采用固相烧结工艺制备了铋层状化合物Sr0.3Ba0.7Bi4-xLaxTi4O15铁电陶瓷。X射线衍射证实:La含量很大的范围内(x=0～1)均形成了层状钙钛矿结构固熔体。Sr0.3Ba0.7Bi3.25La0.75Ti4O15粉料在低温下难以烧结,随着烧结温度的提高,Sr0.3Ba0.7Bi3.25La0.75Ti4O15陶瓷密度增加的同时,产生焦绿石相,但La的加入在一定程度上抑制焦绿石相的形成。Sr0.3Ba0.7Bi3.5La0.5Ti4O15陶瓷的介电常数峰在10kHz时较宽,在100Hz时,介电常数峰被随温度升高而逐渐增大的介电常数所"屏蔽",材料损耗角正切随温度升高而增大,在低频下增加得更快。Bismuth-layered compound, Sr0.3Ba0.7Bi4-xLax Ti4O15, with composition x = 0, 0.25, 0.5, 0.75, and 1.0 were synthesized by the conventional solid-phase reaction process. X-ray diffraction data confirm the formation of single-phase layered perovskite solid solutions over a wide range of La compositions. It is found that obtained Sr0.3Ba0.7Bi3.25 La0.75Ti4O15 powder is hardly sintered at low temperatures. Raising the sintering temperature leads to an increase in density of Sr0.3Ba0.7Bi3.25 La0.75Ti4O15 ceramics and along with a secondary phase having a pyrachlore structure is also produced due to the thermal decomposition reaction. However the doping of La can repress the formation of pyrachlore structure to a certain extent. At higher frequency, such as 10 kHz, dielectric constants of Sr0.3Ba0.7Bi3.25 La0.75Ti4O15 sample have a broad peak. When frequency is at 100 Hz the broad peak is almost shadowed by a gradually increased dielectric constant with an increasing temperature. Dielectric loss of sample Sr0.3Ba0.7Bi3.25 La0.75Ti4O15 increases with increase of temperatures, and change at 100 Hz significantly faster than that at 10 kHz.

关 键 词：铋层状化合物 镧搀杂 介电性能 相变温度 

分 类 号：O482.54[一般工业技术—材料科学与工程] TM271.4[理学—固体物理]