成型压力和掺杂对Na_(1.4)Co_2O_4基材料性能的影响  

Effects of Forming Pressure and Doping on the Properties of Na_(1.4)Co_2O_4-Based Materials

作　　者：厉英[1] 马北越[1] 姜茂发[1] 王臻明[2] 

机构地区：[1]东北大学材料与冶金学院,辽宁沈阳110819 [2]首秦金属材料有限公司炼钢部,河北秦皇岛066000

出　　处：《东北大学学报（自然科学版）》2011年第2期262-265,共4页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金资助项目(51074038)

摘　　要：采用溶胶-凝胶法制备了Na位掺杂Sr和Li(掺杂量分别为0.1,0.2,0.3和0.4)的Na1.4Co2O4基热电材料,研究了成型压力和掺杂对Na1.4Co2O4基材料电导率、Seebeck系数和功率因子等热电性能的影响.采用XRD分析了NaxCo2O4基热电材料的相组成.研究结果表明:掺杂Sr和Li制备的Na1.4Co2O4基材料的主晶相均为γ-Na1.4Co2O4;增加成型压力及掺杂Li均可明显提高材料的电导率、Seebeck系数和功率因子;当Li掺杂量为0.4时,在310 MPa下制备的Na1.4Co2O4基材料的功率因子为7.44 mW.m-1.K-2,明显高于未掺杂试样;适量掺杂Sr也可一定程度上提高材料的热电性能.Na1.4Co2O4-based thermoelectric materials were prepared by sol-gel method,where the Na-site doping was done separately with Sr and Li in different amounts of 0.1,0.2,0.3 and 0.4.The effects of forming pressure and doping on the thermoelectric properties of the materials were investigated,such as the electric conductivity,Seebeck coefficient and power factor.The phase composition of the materials was analyzed by XRD.The results showed that the principal crystalline phase of the prepared Sr/Li-doped Na1.4Co2O4-based materials is γ-Na1.4Co2O4.The electric conductivity,Seebeck coefficient and power factor of the materials can all be increased obviously by increasing the forming pressure and Li-doping.When the doping amount of Li is 0.4,the power factor of the materials prepared under 310A4!MPa comes up to 7.44A4!mW·m-1·K-2,which is much higher than that of the materials without doping.The thermoelectric properties of Na1.4Co2O4-based materials can also be improved to a certain extent by Sr-doping in proper amount.

关 键 词：热电材料 氧化物 热电性能 成型压力 掺杂 

分 类 号：TB34[一般工业技术—材料科学与工程]