Forgotten Layers: How New 2D Materials Were Found express
In chemistry's storeroom, records of substances no one thought were special gathered dust. It turns out that among them hide 2D materials — thin as a sheet of paper, but strong and with unexpected properties. Scientists ran a computer search through databases, and it pulled out 38 candidates that had not been recognized as 2D before.
Five of these materials were recreated in minutes using self-propagating synthesis: the mixture heats itself and turns into the desired substance, like dry firewood bursting into flame from a single match. No external heating is needed — the reaction runs on its own.
Inspired by the found compositions, researchers made 11 more new materials with rare-earth metals: those hiding at the bottom of the periodic table. They turned out to be semiconductors and magnets with different personalities. Now the family of 2D materials is broader, and the search for new ones is faster and cheaper.
Original abstract
as written by the authors arXiv:2608.16644v1
MXenes, two-dimensional transition-metal carbides and nitrides, are typically obtained from MAX phases, yet historical reports suggest a broader, largely unexplored chemical space. Here we combine machine-learning-assisted database mining with experiments to uncover overlooked multilayer (ml) MXenes. Screening of repositories reveals a "Treasure Chest" of 38 previously synthesized but unrecognized ml-MXene candidates. Guided by these findings, we rediscover five MXenes using a rapid, scalable self-propagating high-temperature synthesis that requires no sustained external heating and completes within minutes. Inspired by the identified chemistries, we further realize 11 previously unexplored rare-earth-based M2CT2 MXenes (M= Pr, Nd, Sm, Gd, Tb, Ho, and Tm). Experiments and theory reveal semiconducting behavior and diverse magnetic states across this family. Together, these results expand the MXene family and demonstrate a data-driven strategy for accelerating materials discovery through sustainable methods.
Rare-earth metals are not actually that rare: thulium is more abundant in Earth's crust than silver, but it is hard to extract.