Institute of Geotechnics, Slovak Academy of Sciences; Faculty of Materials, Metallurgy and Recycling, Technical University of Košice.
Faculty of Electrical Engineering and Informatics, Technical University of Košice.
J Vis Exp. 2024 Aug 30(210). doi: 10.3791/67249.
Mechanochemical synthesis is an extremely useful strategy to reach thermoelectric materials due to its solvent-free one-step character, as the targeted thermoelectricity (TE) materials in a nanocrystalline format can be prepared by mere high-energy milling of elemental precursors. Nevertheless, the subsequent densification method (e.g., spark plasma sintering or hot pressing) is required afterward, similarly to other synthetic methodologies. In this study, the simplicity of mechanochemical synthesis is presented for two selected metal chalcogenides, namely copper sulfide (Cu1.8S, digenite) and tin selenide (SnSe, svetlanaite), which are known for high ZT values. These compounds can be prepared via a mechanically induced self-propagating reaction (MSR), which is a combustion-like process instantly yielding the products in a very short timeframe (within 1 min). The occurrence of MSR can be well-tracked by in situ temperature monitoring since an abrupt temperature increase occurs at the moment of MSR. We have developed a device which is capable of monitoring the temperature inside the milling jar every 80 ms during planetary ball milling, and it is therefore possible to very precisely track the moment of MSR ignition. The developed device presents an improvement in the monitoring capabilities in comparison with commercially available analogs. This contribution aims to provide a visual insight into all steps, with simple high-energy ball milling of elements to reach TE materials and in situ temperature monitoring being the central points.
机械化学合成是一种非常有用的策略，可以达到热电材料，由于其无溶剂的一步特性，因为目标热电（TE）材料可以通过仅仅对元素前体进行高能球磨来制备纳米晶格式。然而，随后需要后处理致密化方法（例如，火花等离子体烧结或热压），与其他合成方法类似。在这项研究中，机械化学合成的简单性被呈现为两种选定的金属硫属化物，即硫化铜（Cu1.8S，胆矾）和硒化锡（SnSe，斯韦特兰纳石），它们以高 ZT 值而闻名。这些化合物可以通过机械诱导自蔓延反应（MSR）来制备，这是一种类似于燃烧的过程，在非常短的时间内（在 1 分钟内）立即产生产物。通过原位温度监测可以很好地跟踪 MSR 的发生，因为在 MSR 发生时会出现突然的温度升高。我们开发了一种能够在行星球磨过程中每 80 ms 监测研磨罐内温度的设备，因此可以非常精确地跟踪 MSR 点火的时刻。与市售的类似设备相比，开发的设备在监测能力方面有所提高。本贡献旨在提供所有步骤的直观了解，重点是简单的高能球磨元素以达到 TE 材料和原位温度监测。
