과학자들은 열에서 전기를 생성하는 결정을 만듭니다

열전 특성을 가진 합성 황화물 광물.

열을 전기로 효율적으로 변환하기 위한 노력의 일환으로, 무해한 원료에서 쉽게 접근할 수 있는 재료는 소위 안전하고 저렴한 열전 재료 개발의 새로운 지평을 엽니다. 최근 저널에 발표된 연구에 따르면 합성 구리 금속은 구성의 단순한 변화를 통해 복잡하고 미세한 구조를 획득하여 바람직한 특성의 토대를 마련합니다. 안구안트 키미.

새로운 합성 물질은 구리, 망간, 게르마늄 및 황으로 만들어지며 상당히 간단한 공정으로 생산된다고 프랑스 캉에 있는 CRISMAT 연구소의 CNRS 연구원인 재료 과학자 Emmanuel Gilmou와 연구 교신 저자가 설명합니다. . “분말은 볼 밀링에 의해 기계적으로 혼합되어 사전 결정화 단계를 형성한 다음 600도까지 응축됩니다.[{” attribute=””>Celsius. This process can be easily scaled up,” he says.

Thermoelectric materials convert heat to electricity. This is especially useful in industrial processes where waste heat is reused as valuable electric power. The converse approach is the cooling of electronic parts, for example, in smartphones or cars. Materials used in these kinds of applications have to be not only efficient, but also inexpensive and, above all, safe for health.

However, thermoelectric devices used to date make use of expensive and toxic elements such as lead and tellurium, which offer the best conversion efficiency. To find safer alternatives, Emmanuel Guilmeau and his team have turned to derivatives of natural copper-based sulfide minerals. These mineral derivatives are mainly composed of nontoxic and abundant elements, and some of them have thermoelectric properties.

Now, the team has succeeded in producing a series of thermoelectric materials showing two crystal structures within the same material. “We were very surprised at the result. Usually, slightly changing the composition has little effect on the structure in this class of materials,” says Emmanuel Guilmeau describing their discovery.

The team found that replacing a small fraction of the manganese with copper produced complex microstructures with interconnected nanodomains, defects, and coherent interfaces, which affected the material’s transport properties for electrons and heat.

Emmanuel Guilmeau says that the novel material produced is stable up to 400 degrees Celsius (750 degrees Fahrenheit), a range well within the waste heat temperature range of most industries. He is convinced that, based on this discovery, novel cheaper, and nontoxic thermoelectric materials could be designed to replace more problematic materials.

Reference: “Engineering Transport Properties in Interconnected Enargite-Stannite Type Cu_2+xMn_1−xGeS₄ Nanocomposites” by Dr. V. Pavan Kumar, S. Passuti, Dr. B. Zhang, Dr. S. Fujii, K. Yoshizawa, Dr. P. Boullay, Dr. S. Le Tonquesse, Dr. C. Prestipino, Prof. B. Raveau, Prof. P. Lemoine, Dr. A. Paecklar, Dr. N. Barrier, Prof. X. Zhou, Prof. M. Yoshiya, Dr. K. Suekuni, Dr. E. Guilmeau, 13 September 2022, Angewandte Chemie International Edition.
DOI: 10.1002/anie.202210600

Funding: Agence Nationale de la Recherche, Horizon 2020 Framework Programme, Japan Society for the Promotion of Science