Thermal stability and structural properties of Ta nanopowder synthesized via simultaneous reduction of Ta2O5 by hydrogen and carbon
Thermal stability and structural properties of Ta nanopowder synthesized via simultaneous reduction of Ta2O5 by hydrogen and carbon
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DOI：
10.1007/s10973-014-4136-1
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发表时间：
2014
影响因子：
4.4
通讯作者：
L. Brar;Gourav Singla;Navjot Kaur;O. Pandey
中科院分区：
文献类型：
--
作者：
L. Brar;Gourav Singla;Navjot Kaur;O. Pandey
采用一步化学反应法制备了纳米级钽粉。在600℃下，用原位生成的氢和碳同时还原五氧化二钽(Ta2O5)是制备纳米Ta粉的一种新方法。从热力学计算得到的ΔH值被用来预测体相Ta2O5还原成Ta纳米颗粒的整个机理。X-射线衍射分析表明，最终产物为纳米α-Ta相，少量β-Ta相。用Williamson-Hall公式计算了最终产物中的晶格应变。用差示扫描量热法和空气气氛热重法分析了晶格应变对样品热稳定性的影响。用扫描电子显微镜和透射电子显微镜分析了Ta纳米粉末的形貌和粒度分布。结果表明，产物Ta纳米粉的平均微晶尺寸约为2~7 nm。
Tantalum nanoparticles have been synthesized by the single-step chemical reaction route. Simultaneous reduction of Tantalum Pentoxide (Ta2O5) with the in situ produced hydrogen and carbon at 600 °C is a new approach for the production of Ta nanopowder. ΔHvalues obtained from thermodynamic calculations are used to predict the entire mechanism of reduction of bulk Ta2O5into Ta nanoparticles. The results of X-ray diffraction studies show that the final product consists of predominately nanoα-Ta withβ-Ta as the minority phase. The lattice strain in the final product was calculated using Williamson–Hall formula. The effect of lattice strain on thermal stability of the samples was analyzed by differential scanning calorimetry and thermal gravimetry in the air atmosphere. The morphology and particle size distribution of Ta nanosized powders have been analyzed by scanning electron microscope and transmission electron microscope. The results show that average crystallite size of the product Ta nanopowder is about 2–7 nm.