Hidden in-plane long-range order in an amorphized crystal
Abstract
Solid materials are commonly classified as crystalline or amorphous based on the presence or absence of long-range order.Metal-organic frameworks (MOFs), like other solids,also display markedly different properties and functions in these two phases. Here, we identify a previously unrecognized structural state that retains long-range in-plane translational order while losing order along the stacking direction. Hypothesized since 1941 but not experimentally verified, this intermediate phase emerges in a crystalline MOFs via controlled thermal desolvation, which selectively disrupts the intrinsically weak interlayer interactions while preserving macroscopic structural coherence. Although the resulting material appears amorphous under conventional characterization, systematic synchrotron PXRD, total X-ray scattering, and low-dose high resolution TEM reveal clear in-plane periodicity. This material spontaneously delaminates in water into uniform, high-quality two-dimensional crystalline nanosheets, forming stable colloidal suspensions and exhibiting superlubricity comparable to graphene - but at less than 0.1% of the production cost. Our discovery finds a missing link within the long-standing crystalline-amorphous dichotomy, while providing an inherently scalable route to high-quality 2D crystals, and offering a conceptual and practical advance in phase engineering.
Cite
@article{arxiv.2602.08551,
title = {Hidden in-plane long-range order in an amorphized crystal},
author = {Yin Chen and Anthony E. Phillips and Cheng Fu and Volodymyr Bon and Lei Liu and Xiaoxu Sun and Jiahui Wang and Na Lin and Ruize Xie and Guanqun Cai and Yutong Wang and Jing Ma and Yuhong Liu and Yu Han and Stefan Kaskel},
journal= {arXiv preprint arXiv:2602.08551},
year = {2026}
}