The Relation between Chemical Bonding and Ultrafast Crystal Growth
MetadataShow full item record
Lee, T., & Elliott, S. (2017). The Relation between Chemical Bonding and Ultrafast Crystal Growth. Advanced Materials https://doi.org/10.1002/adma.201700814
Glasses are often described as supercooled liquids, whose structures are topologically disordered like a liquid, but nevertheless retain short-range structural order. Structural complexity is often associated with complicated electron-charge distributions in glassy systems, making a detailed investigation challenging even for short-range structural order, let alone their atomic dynamics. This is particularly problematic for lone-pair-rich, semiconducting materials, such as phase-change materials (PCMs). Here, this study shows that analytical methods for studying bonding, based on the electron-charge density, rather than a conventional atomic pair-correlation-function approach, allows an in-depth investigation into the chemical-bonding network, as well as lone pairs, of the prototypical PCM, Ge$_2$Sb$_2$Te$_5$ (GST). It is demonstrated that the structurally flexible building units of the amorphous GST network, intimately linked to the presence of distinctly coexisting weak covalent and lone-pair interactions, give rise to cooperative structural-ordering processes, by which ultrafast crystal growth becomes possible. This finding may universally apply to other PCMs.
chemical bonding, crystal growth, DFT calculations, phase-change materials
Is supplemented by: https://doi.org/10.17863/CAM.8695
The authors acknowledge financial support from the Engineering and Physical Sciences Research Council (UK). The AIMD simulations were partially performed using the Cambridge High-Performance Computing Facility (Darwin).
EPSRC (via University of Southampton) (EP/M015130/1)
Embargo Lift Date
External DOI: https://doi.org/10.1002/adma.201700814
This record's URL: https://www.repository.cam.ac.uk/handle/1810/263184
Attribution 4.0 International, Attribution 4.0 International, Attribution 4.0 International, Attribution 4.0 International