多元掺杂LaGaO_3基稀土复合氧化物的制备与导电性能  

Preparation and Electrical Properties of LaGaO_3-based Rare Earth Composite Oxides Doped with Multielement

作　　者：赵捷[1,2] 王志奇[1] 马永昌[1,2] 马叙[1] 包俊成[1] 刘技文[1,2] 

机构地区：[1]天津理工大学材料科学与工程学院,天津300191 [2]天津市光电显示材料与器件重点实验室,天津300191

出　　处：《机械工程材料》2009年第3期35-38,共4页Materials For Mechanical Engineering

基　　金：国家自然科学基金资助项目(10704054);天津市科技发展计划项目(06TXTJJC14600)

摘　　要：采用改进的固相反应法合成了锶、镁与铁或钴多元掺杂的LaGaO_3基稀土复合氧化物La_(0.8)Sr_(0.2)Ga_(0.72)Mg_(0.20)Fe_(0.08)O_(2.8)(LSGMF)和La_(0.8)Sr_(0.2)Ga_(0.72)Mg_(0.20)Co_(0.08) O_(2.8)(LSGMC),利用EDS、XRD及SEM等方法对LSGMF和LSGMC的化学成分、物相组成及显微组织等进行了分析;采用直流四端子法测量了两者在350～850℃温度区间的电导率。结果表明:经1 400℃烧结后, LSGMF和LSGMC均形成单一正交钙钛矿结构;两者除含少量钙外,不合其他杂质元素;在测试温度范围,材料的电导率与温度的关系分区间符合Arrhenius方程,在较低温阶段(350～500℃)具有较低的导电活化能(E_a<0.3 eV);与仅用锶、镁双掺杂的LSGM相比,LSGMF和LSGMC具有较高的电导率。LaGaO3-based rare earth composite oxides of La0.8Sr0.2Ga0.72Mg0.20Fe0.08O2.8（LSGMF） and La0.8Sr0.2Ga0.72Mg0.20Co0.08O2.8（LSGMC） doped with St, Mg and Fe or Co were synthesized by improved solid reaction method. The composition, phase structure and microstructure of LSGMF and LSGMC samples were analyzed by means of EDS,XRD and SEM. The electrical conductivities of LSGMF and LSGMC as a function of the temperature were measured by DG four-probe technique in the temperature range of 350--850 ℃. The results show that a single phase material of orthorhombic perovskite-type structure was formed after sintering in air at 1 400 ℃ in LSGMF and LSGMC. Other impurity elements were not found except for small amount of Ca in LSGMF and LSGMC samples. The relationship between temperature and the conductivity of LSGMF and LSGMC conformed to the Arrhenius equation in the temperature range of 350 -- 500 ℃ and 500 -- 850 ℃. The activation energies of LSGMF and LSGMC were low at 350- 500 ℃ （Ea d0. 3 eV）. The conductivities of LSGMF and LSGMC were considerably increased compared with Sr, Mg-doped LSGM.

关 键 词：镓酸镧 多元掺杂 过渡金属 稀土复合氧化物 

分 类 号：TM911.4[电气工程—电力电子与电力传动]