Optimizing the thermoelectric performance of FeVSb half-Heusler compound via Hf–Ti double dopingстатья
Статья опубликована в высокорейтинговом журнале
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Дата последнего поиска статьи во внешних источниках: 13 января 2021 г.
Аннотация:FeVSb-based half-Heusler (HH) compound has recently been identified as promising medium-high temperature thermoelectric (TE) materials for power generation applications. In this study, enhanced thermoelectric performance of Fe(V0.8Hf0.2)1-xTixSb (x = 0.0, 0.2, 0.4, 0.5, 0.6) HH alloys by Hf-Ti dual-doping was studied in a temperature range from 100 to 900 K. A high content of Ti doping not only optimized the carrier concentration but also reduced the lattice thermal conductivity, which all contribute to high zT. As a result, a zT value was increased by ~20% at 873 K for Fe(V0.8Hf0.2)0.8Ti0.2Sb compound. Hf-Ti dual doping significantly reduced the lattice thermal conductivity due to enhanced point defect scattering attributed to mainly mass fluctuations. Hence, suppress the material’s total thermal conductivity. A reduction of ~20% was obtained for the Fe(V0.8Hf0.2)0.8Ti0.2Sb sample, compared with the single Hf-doped FeVSb sample and of ~80% compared to FeVSb at room temperature. The low lattice thermal conductivity close to a theoretical minimum was obtained for the specimen with x = 0.6 and value of 1.25 W m-1 K-1 at 873 K.