title: Hybrid glasses from strong and fragile metal-organic framework liquids.
abstract: Hybrid glasses connect the emerging field of metal-organic frameworks (MOFs) with the glass formation, amorphization and melting processes of these chemically versatile systems. Though inorganic zeolites collapse around the glass transition and melt at higher temperatures, the relationship between amorphization and melting has so far not been investigated. Here we show how heating MOFs of zeolitic topology first results in a low density 'perfect' glass, similar to those formed in ice, silicon and disaccharides. This order-order transition leads to a super-strong liquid of low fragility that dynamically controls collapse, before a subsequent order-disorder transition, which creates a more fragile high-density liquid. After crystallization to a dense phase, which can be remelted, subsequent quenching results in a bulk glass, virtually identical to the high-density phase. We provide evidence that the wide-ranging melting temperatures of zeolitic MOFs are related to their network topologies and opens up the possibility of 'melt-casting' MOF glasses.
authors: Department of Materials Science and Metallurgy, University of Cambridge, Charles Babbage Road, Cambridge CB3 0FS, UK.
authors: Thomas D
authors: TD
authors: Bennett
authors: Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK.
authors: Jin-Chong
authors: JC
authors: Tan
authors: Section of Chemistry, Aalborg University, DK-9220 Aalborg, Denmark.|State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China.
authors: Yuanzheng
authors: Y
authors: Yue
authors: Department of Materials Science and Metallurgy, University of Cambridge, Charles Babbage Road, Cambridge CB3 0FS, UK.
authors: Emma
authors: E
authors: Baxter
authors: Department of Materials Science and Metallurgy, University of Cambridge, Charles Babbage Road, Cambridge CB3 0FS, UK.
authors: Caterina
authors: C
authors: Ducati
authors: Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK.
authors: Nick J
authors: NJ
authors: Terrill
authors: International Center of Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan.
authors: Hamish H-M
authors: HH
authors: Yeung
authors: Institute of Mathematics, Physics and Computer Science, Department of Physics, Aberystwyth University, Aberystwyth SY23 3BZ, UK.
authors: Zhongfu
authors: Z
authors: Zhou
authors: Institute of Mathematics, Physics and Computer Science, Department of Physics, Aberystwyth University, Aberystwyth SY23 3BZ, UK.
authors: Wenlin
authors: W
authors: Chen
authors: Department of Materials Science and Metallurgy, University of Cambridge, Charles Babbage Road, Cambridge CB3 0FS, UK.|Lehrstuhl für Anorganische Chemie II, Fakultät für Chemie und Biochemie, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany.
authors: Sebastian
authors: S
authors: Henke
authors: Department of Materials Science and Metallurgy, University of Cambridge, Charles Babbage Road, Cambridge CB3 0FS, UK.
authors: Anthony K
authors: AK
authors: Cheetham
authors: Department of Materials Science and Metallurgy, University of Cambridge, Charles Babbage Road, Cambridge CB3 0FS, UK.|State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China.|Institute of Mathematics, Physics and Computer Science, Department of Physics, Aberystwyth University, Aberystwyth SY23 3BZ, UK.
authors: G Neville
authors: GN
authors: Greaves