中文摘要：

采用熔炼、退火结合放电等离子烧结的方法制备了名义成分为MnSix（x=1.60、1.65、1.68、1.73、1.81、1.85）的高锰硅（HMS,Higher Manganese Silicide）块体材料.物相分析结果表明,随着Si初始用量x的增加,HMS（Mn15Si26）相各衍射峰强度先增强后减弱.当x〈1.73时,样品物相组成为HMS相和少量MnSi相,当x≥1.73时,样品物相组成为HMS相和少量Si相.体系的热电性能受MnSi相和Si相的影响,热电性能分析结果表明：随着Si名义含量x的增大,试样电导率逐渐降低,赛贝克系数逐渐增大,热导率先降低后增高.其中,名义成分为MnSi1.68的试样由于具有最高的电性能（功率因子）和较低的热导率,从而具有最好的热电性能,在400℃时其无量纲ZT值达到0.36.

英文摘要：

Higher manganese silicides（HMS） bulk materials with the nominal compositions of MnSix（x = 1.60,1.65,1.68,1.73,1.81,1.85） were prepared by arc-melting,annealing and spark plasma sintering.The phase struc-tures and morphologies of the samples were investigated,and their thermoelectric properties were measured from 300℃ to 600℃.The analyses of phase compositions revealed that the intensity of X-ray diffraction peaks was firstly enhanced and then weakened along with x value increasing.The phase composition were of HMS and MnSi for x1.73 samples,and were of the HMS and Si for x≥1.73 samples.It was shown that the thermoelectric proper-ties of the samples were affected strongly by the metallic MnSi phase and the semiconducting Si phase.The elec-trical conductivity decreased continuously,while the Seebeck coefficients increased with x value increasing.In ad-dition,the thermal conductivity decreased firstly and then increased with x value increasing.Furthermore,it was showed that the thermal conductivity remained constant at lower temperature and then increased sharply because of the contribution of electron thermal conductivity at temperature higher than 450℃.The MnSi1.68 sample had the highest dimensionless figure of merit ZT 0.36 at 400℃,as a result of its highest electrical performance（power fac-tor） and moderately low thermal conductivity.