Enhancement of thermoelectric properties of SrTiO3/LaNb–SrTiO3 composite by different doping levels

• 来源期刊: 中国物理B（英文版）
• 关键词: thermoelectric materials SrTiO3/LaNb–SrTiO3 composite hydrothermal method strontium ti-tanate
• 年，卷（期）: 2018,（4）
• 页码范围: 117-122
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/27/4/048401

摘要

Strontium titanate (STO) is an n-type oxide thermoelectric material, which has shown great prospects in recent years. The doping of La and Nb into STO can improve its power factor, whereas its thermal conductivity is still very high. Thus, in order to obtain a high thermoelectric figure-of-merit zT , it is very important to reduce its thermal conductivity. In this paper, using a combination of a hydrothermal method and a high-efficiency sintering method, we succeed in preparing a composite of pure STO and LaNb-doped STO, which simultaneously realizes lower thermal conductivity and higher Seebeck coefficient, therefore, the thermoelectric properties of STO are significantly improved. In the SrTiO3/LaNb–SrTiO3 bulk samples, the lowest thermal conductivity is 2.57 W·m?1·K?1 and the highest zT is 0.35 at 1000 K for the STO/La10Nb20–STO sample.