用甘氨酸法合成Sm_(0.1)Ca_(0.9)MnO_3粉体及热电性能表征  

Glycine nitrate process for Sm_(0.1)Ca_(0.9)MnO_3 powder and their thermoelectric properties

作　　者：仲洪海[1] 王文龙[1] 张海青[1] 蒋阳[1] 余大斌[2] 

机构地区：[1]合肥工业大学材料科学与工程学院,合肥230009 [2]解放军电子工程学院,合肥230037

出　　处：《粉末冶金材料科学与工程》2011年第1期32-37,共6页Materials Science and Engineering of Powder Metallurgy

基　　金：中国博士后科学基金资助项目(20100470827);校博士后科学基金资助项目(103035037)

摘　　要：以Sm2O3、CaCO3、乙酸锰和硝酸为原料,采用改进的甘氨酸-硝酸盐法制备Sm0.1Ca0.9MnO3粉末,经过压制和烧结制备热电材料。用X射线衍射、扫描电镜和激光粒度仪等对粉末进行表征,并研究该热电材料的性能。结果表明,Sm0.1Ca0.9MnO3粉末为单一的钙钛矿相结构,粉末体为细小晶粒的团聚体,呈链状结构,粒度范围1.436~12.118μm。Sm0.1Ca0.9MnO3粉体的压形规律符合黄培云压制方程,压制模量M为1.124 7 MPa,非线性指数m为4.544 5;随着Sm3＋的掺杂,Sm0.1Ca0.9MnO3材料的电阻率减小;随温度升高,发生半导体向金属的转变现象,在473 K时Sm0.1Ca0.9MnO3块体的功率因子达到6.0×10-4 W/（m-K2）。因此,Sm0.1Ca0.9MnO3是1种具有潜在应用前景的n型热电材料。Powder of thermoelectric oxide Sm0.1Ca0.9MnO3 was synthesized by modified glycine nitrate process（MGNP）,using Sm2O3,CaCO3,Mn（CH3COO）2 and nitric acid as raw materials.The characteristics and properties of Sm0.1Ca0.9MnO3 powder were detected by XRD,SEM and laser granulometer.The results show that the powder with pure perovskite structure is composed of fine crystal grains,owns chain shape and the particle size is in the range of 1.436~12.118 μm.The compaction results reveal that the compaction module and the nonlinear exponent of the powder compaction are about 1.124 7 MPa and 4.544 5 calculated from HUANG Pei-yun＇s compacting equation,respectively.The electrical resistivity of sintered body decreases with the dopant of Sm3＋.The materials show the semiconductor-metal transition with the increase of the temperature.The highest power factor,6.0×10-4 W/（m-K2）,has been obtained at 473 K.It will be promising to be thermoelectric material for thermoelectric devices.

关 键 词：Sm0.1Ca0.9MnO3 甘氨酸-硝酸盐法 热电性能 

分 类 号：TN304.82[电子电信—物理电子学]