(安徽工業(yè)大學(xué) 冶金工程學(xué)院，馬鞍山 243032)
摘 要: 采用微波加熱4 min成功合成了Bi1?xCuSeO和BiCu1?ySeO (x, y=0, 0.02, 0.03, 0.04, 0.05)，隨后在650 ℃下采用放電等離子燒結(jié)5min獲得相對(duì)致密度約95%的熱電塊體，并對(duì)它們的物相組成、微觀結(jié)構(gòu)、電輸運(yùn)性能進(jìn)行系統(tǒng)研究。X衍射分析表明，樣品衍射峰與四方晶系BiCuSeO標(biāo)準(zhǔn)卡片吻合，但部分樣品中含有少量雜質(zhì)；微觀結(jié)構(gòu)分析結(jié)果表明，空位樣品晶粒呈針狀、條狀，平均晶粒尺寸約為2~4 μm；電性能分析表明，雖然空位樣品的塞貝克系數(shù)相比非空位BiCuSeO樣品的略有降低，但空位處理顯著提高了樣品的導(dǎo)電性，其中Bi空位濃度對(duì)Bi1?xCuSeO電阻率的影響較不規(guī)律，BiCu1?ySeO樣品電阻率隨Cu空位濃度提高呈規(guī)律性降低、導(dǎo)電性增強(qiáng)。綜合來看，空位處理可以大幅提高樣品綜合電性能即功率因子，其中Bi0.96CuSeO的功率因子最高達(dá)到395.1 μW/(K2?m)，BiCu0.95SeO功率因子最高達(dá)到481.5 μW/(K2?m)，分別為非空位BiCuSeO樣品最高功率因子的2.1倍和2.5倍。
關(guān)鍵字: 鉍銅硒氧；微波合成；Bi/Cu空位；電阻率；功率因子
（School of Metallurgical Engineering, Anhui University of Technology, Ma’anshan 243032, China）
Abstract:The series of oxyselenides thermoelectric compounds Bi1-xCuSeO and BiCu1-ySeO (x, y=0, 0.02, 0.03, 0.04, 0.05) were successful synthesized in 4 min via microwave heating for the first time, and the corresponding bulks were subsequent fabricated with spark plasma sintering at 650 ℃ for 5 min. The phase composition, microstructure and electrical transport properties were investigated. The analysis of XRD patterns show that the diffraction peaks for all samples are matching to tetragonal BiCuSeO standard card. However, some samples contain small amounts of impurities. The analysis of microstructure shows that the grains of samples with vacancy show needle-like and strip-like, with average grain sizes of about 2-4 μm. The analyses of electrical transport properties show that the seebeck coefficients of samples with vacancy are slightly lower than that of non-vacancy BiCuSeO, nevertheless, the vacancy treatment significantly improves the conductivity. Bi vacancy concentration has an irregular influence on the resistivity of Bi1-xCuSeO samples, and the resistivity of BiCu1-ySeO samples decrease regularly with the increase of Cu vacancy concentration, respectively. In general, the vacancy treatment can greatly improve the comprehensive electrical performance, namely, enhance the power factor, the maximum power factors for Bi0.96CuSeO and BiCu0.95SeO are 395.1 and 481.5 μW/(K2？m), respectively, which are 2.1 times and 2.5 times compared to that of the non-vacancy BiCuSeO.
Key words: BiCuSeO; microwave synthesis; Bi/Cu vacancy; resistivity; power factor
