Noble-metal-based chalcogenide materials recently gained massive attention in the field of thermoelectrics. In most cases, materials are synthesized using (i) high-temperature solid-state reactions or (ii) soft chemical methods where temperature requirements are lower than those of solid-state reactions (generally below 400 °C). Herein, we present a simple, surfactant-free, room-temperature, and energy-efficient synthesis of Ag₃CuS₂ nanocrystals. The present synthesis technique is scalable and capable of gram-scale production. A spark plasma sintering (SPS) pressed sample exhibits ultralow thermal conductivity (∼0.31 W/mK at room temperature). We found that Ag₃CuS₂ exhibits low sound velocity, as well as a non-Debye-like behavior based on a low-temperature heat capacity measurement. A high degree of anharmonicity of bonding, soft vibrations modes, and nanoscale grain boundary scattering in Ag₃CuS₂ lead to ultralow thermal conductivity, which can be important for thermoelectrics, optoelectronics, and thermal barrier coating applications.

中文翻译：

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纳米晶 Ag3CuS2 的室温合成和低导热率


贵金属基硫系材料最近在热电领域引起了广泛关注。在大多数情况下，材料是使用（i）高温固态反应或（ii）软化学方法合成的，其中温度要求低于固态反应（通常低于400°C）。在此，我们提出了一种简单、无表面活性剂、室温、节能的 Ag ₃ CuS ₂ 纳米晶体的合成方法。本发明的合成技术是可扩展的并且能够进行克级生产。放电等离子烧结 (SPS) 压制样品表现出超低导热率（室温下约 0.31 W/mK）。我们发现 Ag ₃ CuS ₂ 表现出低声速，以及基于低温热容测量的非德拜行为。 Ag ₃ CuS ₂ 中的高度非和谐键合、软振动模式和纳米级晶界散射导致超低导热率，这对于热电、光电子和电子学非常重要。热障涂层应用。