CAJ | 학술논문

采用熔炼-淬火-高能球磨-放电等离子体烧结工艺,制备GeTe-PbTe合金Ge0．75 Pb0．25 Te及Se替代合金Ge0．75 Pb0．25 Te0．5 Se0．5,研究和比较它们的物相、微结构及热电性能.结果表明：母合金Ge0．75 Pb0．25 Te由分别以GeTe和PbTe为基的两相组成,具有调幅分解组织,而Se替代合金Ge0．75 Pb0．25 Te中50%Te的合金变成以GeTe为基的单一固溶体,且存在大量的较小孪晶组织,两种合金都表现为p型半导体导电特性,固溶的Pb和Se原子改善了化合物的载流子浓度及能带结构,导致合金的Seebeck系数大幅度增加,固溶的Se及Pb原子、孪晶组织和晶界形成多尺度的声子散射中心,导致合金具有极低的热导率,热电优值ZT大幅度提高,673 K下,从Ge0．75 Pb0．25 Te的0．45提高到Ge0．75 Pb0．25 Te0．5 Se0．5的1．6.
채용용련-쉬화-고능구마-방전등리자체소결공예,제비GeTe-PbTe합금Ge0．75 Pb0．25 Te급Se체대합금Ge0．75 Pb0．25 Te0．5 Se0．5,연구화비교타문적물상、미결구급열전성능.결과표명：모합금Ge0．75 Pb0．25 Te유분별이GeTe화PbTe위기적량상조성,구유조폭분해조직,이Se체대합금Ge0．75 Pb0．25 Te중50%Te적합금변성이GeTe위기적단일고용체,차존재대량적교소련정조직,량충합금도표현위p형반도체도전특성,고용적Pb화Se원자개선료화합물적재류자농도급능대결구,도치합금적Seebeck계수대폭도증가,고용적Se급Pb원자、련정조직화정계형성다척도적성자산사중심,도치합금구유겁저적열도솔,열전우치ZT대폭도제고,673 K하,종Ge0．75 Pb0．25 Te적0．45제고도Ge0．75 Pb0．25 Te0．5 Se0．5적1．6.
The alloy Ge0. 75 Pb0. 25 Te and its Se substitution alloy Ge0. 75 Pb0. 25 Te0. 5 Se0. 5 were prepared by reaction melting, quenching, high-energy ball milling and spark plasma sintering techniques. The phases, microstructures and thermoelectric properties for both alloys were investigated. Experimental results show that the alloy Ge0. 75 Pb0. 25 Te consists of both GeTe-based and PbTe-based phases with spinodal decomposition microstructures while the Se substitution alloy Ge0. 75 Pb0. 25 Te0. 5 Se0. 5 is of the GeTe-based solid solution single phase with a lot of twinning microstructures. The alloys show a nature of p-type conduction. The solute Pb and Se atoms in the lattice modify the band structure of the compounds, leading to a considerable increase in Seebeck coefficient. The solute Pb and Se atoms, twinning microstructures and grain boundaries form panoscopic phonon scattering centers, result in an extremely low thermal conductivity of the alloy and a dramatic increase of its figure of merit ZT from 0. 45 for the alloy Ge0. 75 Pb0. 25 Te to 1. 6 for the alloy Ge0. 75 Pb0. 25 Te0. 5 Se0. 5 at 673 K.