A series of n-type Mg(SiSn)Bi compounds with 0≤≤0.02 were successfully synthesized through a combined approach involving solid-state reaction, high-pressure synthesis, and spark plasma sintering techniques. The method yielded homogeneously distributed single-phase materials at the micron scale, although minor compositional variations were detected within nanoscale precipitates embedded in the grains. The sample with Bi content of 0.01 exhibited enhanced thermoelectric properties, reaching a peak thermoelectric figure of merit () of 1.45 at 700 K while maintaining an average of about 1.1 over the temperature range of 300−773 K. The enhancement in thermoelectric performance is ascribed to the optimized carrier concentration, band convergence, and refined microstructure. The findings suggest a simplified approach to doping that could be beneficial in creating high-performance thermoelectric materials for energy conversion.

中文翻译：

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高压下Bi掺杂增强Mg2Si0.3Sn0.7的热电性能

通过固相反应、高压合成和放电等离子烧结技术相结合的方法，成功合成了一系列0≤≤0.02的n型Mg(SiSn)Bi化合物。该方法产生了微米级均匀分布的单相材料，尽管在嵌入晶粒的纳米级沉淀物中检测到了微小的成分变化。 Bi含量为0.01的样品表现出增强的热电性能，在700 K时达到1.45的峰值热电品质因数()，同时在300−773 K的温度范围内保持平均值约1.1。热电性能的增强归因于热电性能的增强。优化的载流子浓度、能带收敛和细化的微观结构。研究结果表明，一种简化的掺杂方法可能有利于创造用于能量转换的高性能热电材料。