Enhancement of thermoelectric performance of Sr_0.7Ba_0.3Nb₂O_6−δ ceramics by lanthanum doping

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• 作者：Yi Li ; Jian Liu ; ^{liujjx@sdu.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Yacui Zhang ; Yucheng Zhou ; Jichao Li ; Wenbin Su ; Jinze Zhai ; Hongchao Wang ; Chunlei Wang
• 关键词：Thermoelectric ; Sr0.7Ba0.3Nb2O6&minus ; δ ; La-doping ; ZT
• 刊名：Ceramics International
• 出版年：2016
• 出版时间：January 2016
• 年：2016
• 卷：42
• 期：1
• 页码：1128-1132
• 全文大小：818 K

文摘

Thermoelectric properties of La doped Sr_0.7Ba_0.3Nb₂O_6-δ ceramics were investigated in the temperature range from 323 K to 1073 K. The electrical resistivity decreases due to the subsitution of La for Sr, leading to the enhancement of thermoelectric power factor in the heavily doped sample Sr_0.50La_0.20Ba_0.30Nb₂O_6−δ. Slight La-doping promotes the growth of Sr_0.7Ba_0.3Nb₂O_6−δ grains, but it will be impeded in the heavily La doped samples. Thus, La heavily doped sample Sr_0.50La_0.20Ba_0.30Nb₂O_6−δ shows low thermal conductivity because of the phonon scattering caused by grain boundaries. The highest thermoelectric performance was observed in the sample Sr_0.50La_0.20Ba_0.30Nb₂O_6−δ, and the thermoelectric figure of merit reaches the maximum value ~0.22 at 1073 K.