高度织构NaCo_2O_4陶瓷的热电性能研究  

Thermoelectric Properties of Highly Textured NaCo_2O_4 Ceramics

作　　者：程金光[1] 隋郁[1] 付海金[1] 千正男[1] 刘志国[1] 苗继鹏[1] 苏文辉[1] 

机构地区：[1]哈尔滨工业大学理学院应用物理系凝聚态科学与技术研究中心,哈尔滨150001

出　　处：《无机材料学报》2006年第2期387-391,共5页Journal of Inorganic Materials

基　　金：国家自然科学基金(10304004)哈尔滨工业大学校基金(HIT.2002.46)

摘　　要：结合固相反应法和冷高压成型技术制备了具有高度结晶各向异性的热电氧化物陶瓷 NaCo2O4．X射线衍射和扫描电子显微镜测试表明冷高压压制成型后烧结有利于样品内层状晶粒的c轴沿着施压方向取向排列,形成高度织构．室温以下热电性质的测试表明,电阻率ρ和 Seebeck系数S呈现出金属性,S>0,属于p型热电材料．与其他方法制备的样品进行比较, 虽然晶界或点缺陷对声子散射的减少导致上述样品的热导率偏高,但是由于ρ降低、S升高, 使得热电品质因子ZT值提高,300K时ZT值达到0．013．NaCo2O4 thermoelectric oxide ceramics with high crystallographic anisotropy were synthesized successfully by combining the traditional solid-state reaction and cold high pressure compacting method. XRD and SEM measurements show that the sintering after cold-high-pressure compacting is helpful to align the c-axis of layered grain within the sample along the pressing direction, i.e. the sample is highly textured. The thermoelectric properties of NaCo2O4, measured below room temperature exhibit a metallic behavior S. The sign of S is positive, indicating a p-type in both the resistivity p and Seebeck coefficient thermoelectric material. Compared with the samples prepared with other methods, although the thermal conductivity is higher due to the suppression of the phonon scattering by grain boundary or point defect, the above sample exhibits lower p and higher S which leads to the improvement of the ZT value that reaches 0.013 at 300K.

关 键 词：NaCo2O4陶瓷 高度织构 热电性能 

分 类 号：TN37[电子电信—物理电子学]