Enhanced thermoelectric performance of spark plasma sintered p-type Ca_(3-x)Y_(x)Co_(4)O_(9+δ)systems  

作　　者：J.S.Cha D.H.Kim H.Y.Hong K.Park 

机构地区：[1]Faculty of Nanotechnology and Advanced Materials Engineering,Sejong University,Seoul,05006,Republic of Korea

出　　处：《Journal of Materials Science & Technology》2020年第20期212-222,共11页材料科学技术（英文版）

基　　金：This research was supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.2017R1D1A1B03031196)。

摘　　要：Highly textured dense Ca3-xYxCo4 O9+δ(0≤x≤0.3)samples were fabricated by combining sol-gel process with spark plasma sintering(SPS).Y^3+substitution for Ca^2+simultaneously increased the Seebeck coefficient and reduced the thermal conductivity.The latter was attributed to the increase in lattice anharmonicity,structural distortion,and grain boundary area,which enhanced the phonon scattering.Ca2.7Y0.3Co4 O9+δshowed the largest dimensionless figure-of-merit(ZT=0.194)at 1073 K because it had the largest Seebeck coefficient and the lowest thermal conductivity.This ZT value was 55%larger than that of undoped Ca3 Co4 O9(0.125 at 1073 K).Therefore,Y^3+substitution,sol-gel powder synthesis,and SPS are highly effective for enhancing the thermoelectric prope rties of Ca_(3)Co_(4)O_(9).

关 键 词：Electrical conductivity Ca_(3)Co_(4)O_(9) Thermoelectric properties Seebeck coefficient Thermal conductivity Spark plasma sintering 

分 类 号：TB34[一般工业技术—材料科学与工程]