Buckingham Mark A, Shea Joshua J, Quan Kho Zhi, Lo Pok Man Ethan, Swindell Joshua, Xiao Weichen, Lewis David J, Eggeman Alex S, Hunt Simon A
Department of Materials, The University of Manchester, Oxford Road, M13 9PL, Manchester, UK.
Commun Chem. 2025 Mar 5;8(1):65. doi: 10.1038/s42004-025-01463-9.
High entropy metal chalcogenides are an emergent class of materials that have shown exceptional promise in applications such as energy storage, catalysis, and thermoelectric energy conversion. However, the stability of these materials to factors other than temperature are as yet unknown. Here we set out to assess the stability of the high entropy metal sulfide (MnFeCuAgZnCd)S with high pressure (up to 9 GPa), compared to an enthalpically stabilised AgCuS, and a quasi-stable (MnFeZnCd)S. Compression and pressure-annealing of (MnFeCuAgZnCd)S showed diffusion-controlled time and pressure dependent exsolution of jalpaite (AgCuS) from the bulk. Bulk materials characterisation found minor phase impurities and possible elemental localisations in (MnFeCuAgZnCd)S prior to pressure-annealing. To gain deeper understanding of the material pre- and post-pressure annealing at the nanoscale an advanced technique was used which combined machine learning, unsupervised clustering analysis of STEM-EDX mapping with scanning precession electron diffraction (SPED), which revealed a chemically distinct post-pressure annealed jalpaite exsolved from (MnFeCuAgZnCd)S.
高熵金属硫族化物是一类新兴材料，在能量存储、催化和热电能量转换等应用中展现出了卓越的前景。然而，这些材料对温度以外因素的稳定性尚不清楚。在此，我们着手评估高熵金属硫化物（MnFeCuAgZnCd）S在高压（高达9吉帕）下的稳定性，并将其与焓稳定的AgCuS以及准稳定的（MnFeZnCd）S进行比较。（MnFeCuAgZnCd）S的压缩和压力退火显示，辉铜矿（AgCuS）从整体中以扩散控制的方式随时间和压力进行脱溶。大块材料表征发现，在压力退火之前，（MnFeCuAgZnCd）S中存在少量相杂质以及可能的元素局部化现象。为了在纳米尺度上更深入地了解材料在压力退火前后的情况，我们使用了一种先进技术，该技术将机器学习、扫描透射电子显微镜 - 能谱（STEM - EDX）映射的无监督聚类分析与扫描进动电子衍射（SPED）相结合，结果显示从（MnFeCuAgZnCd）S中脱溶出了化学性质不同的压力退火后辉铜矿。
