Lawrie B Skinner

Research Scientist

2001-05 MSci Physics, Bristol Univ., UK.
2005-08 Ph.D. Physics, Bristol Univ., UK (Barnes group).
2009-09 Postdoc., Civil & Enviro. Eng., UC Berkeley (Monteiro group).
2010-13 Postdoc., Mineral Physics Inst., Stony Brook (Parise group).
2013- Research Scientist, Mineral Physics Inst., Stony Brook.

Office: Advanced Photon Source, Argonne National Lab, Argonne, IL 60439.
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Research Interests

I study liquid and amorphous materials with the aim of improving our understanding of these materials at the atomic scale. My current work is best categorized into three parts:

Water and molecular liquids

  • Connecting the unusual properties of water to its atomic structure.

  • Conditions of deep supercooling, high electric field, super-saturation etc.

New oxide glasses

  • Novel silica-free oxide glasses, such as aluminates, have useful properties including high stiffness and good infrared transparency.

  • Earth-relevant and industry-relevant silicates, such as CaSiO3. Liquid fragility and the glass transition.

Melts at extreme conditions

  • Unusual behaviour such as Polyamorphism at high temperatures and/or pressures. The phase diagram (upper right) shows a polyamorphic, liquid-liquid transition.

  • High temperature melts (Tmelt>2000K), such as Y2O3. The image (lower right) shows a floating molten drop being laser heated.

Favourite techniques: Synchrotron x-ray scattering, neutron scattering, Aerodynamic levitation, laser heating, pair distribution function (PDF), Molecular Dynamics (MD) simulations.

Publications (peer reviewed)

  1. The structure of water around the compressibility minimum

    Skinner et al. JCP 141 (2014)
  2. High energy x-ray scattering was used to determine the gOO(r) function of liquid water over a wide temperature range.

    Diffraction patterns and gOO(r) data download.
  3. Molten Uranium dioxide structure and dynamics

    Skinner et al. Science 346 (2014)
  4. UO2 was melted and studied using synchrotron x-ray scattering.

    See highlight articles on the Argonne National Lab, Stony Brook university, American ceramics, and science news websites.

    Diffraction data, paper and supplemental info download.

  5. Structure of Ba-Ti-Al-O glasses produced by aerodynamic levitation and laser heating.

    Kidkhunthod et al. Phys. Rev. B. 90 (2014)
  6. Barium-alumino-titanate glasses were investigated using multiple techniques. The Al coordination of this glass is found to be highly tetrahedral, whereas the Ti-O coordination is found to be a mixture of mainly 4 and 5 coordinated units.

  7. Structure of molten titanium dioxide.

    Alderman et al. Phys. Rev. B. 90 (2014)
  8. The structure of molten TiO2 is found to be dominated by TiO5 units, analgous to liquid SiO2 at 27GPa and metastable 5-coordinated polymorphs are predicted.

  9. Packing and the structural transformations in liquid and amorphous oxides from ambient to extreme conditions.

    Zeidler et al. PNAS 111 (2014)
  10. We found that the local coordination (the number of oxygen atoms around each cation) is highly sensitive to the oxygen packing fraction. These results provide a structure-density map for understanding the structural changes across a broad range of liquid and glassy oxides (see Figure). This finding guides our understanding of a diverse range of phenomena from magma in the deep mantle, to formation of the glass fibres upon which the internet depends.

    See highlight article here

  11. Ultrafast X-ray probing of water structure below the homogeneous ice nucleation temperature.

    Sellberg et al. Nature 510 (2014)
  12. The structure of liquid water was measured at deeply supercooled temperatures down to 227K (-46 °C, left image). This was achieved using extremely short x-ray pulses (<100 fs) incident upon micron sized droplets of water (right image). These measurements at the proposed liquid-liquid transition temperature, help us understand water's abnormal properties. These cold, container-less conditions are also relevant to liquid water in space.

    See highlight article here.

  13. Low Cation Coordination in Oxide Melts.

    Skinner et al. Phys. Rev. Lett. 112 (2014)
  14. Structural knowledge of many oxide melts above T~2000K has been limited because traditional containers soften and contaminate the sample. Ambiguities also arise from the overlap of structural correlations.

    Here these problems were solved for molten yttria by levitation, and measuring the full set of Y-Y, Y-O and O-O pair distribution functions. This allowed us to see that the molten Y-O coordination was significantly lower than the crystalline solid. Similar measurements supported with molecular dynamics simulations on a range of oxide melts and glasses finds a general trend with all but the highest field strength cations (e.g. Si, Ge) having lower-than-crystal M-O coordination (M=cation).

    Diffraction data download

    See highlight articles here, here and here

  15. Atomistic insight into viscosity and density of silicate melts under pressure.

    Wang et al. Nature Communications 5 (2014)
  16. Silicate melts can be broadly characterised by their fraction of non-bridging oxygen per tetrahedron (NBO/T). Those with NBO/T<1 (polymerised melts) often display the unusual property of decreasing viscosity with increasing pressure. Using diffraction and MD simulations we show that this abnormal viscosity behavior occurs below the tetrahedral packing limit (vertical blue band). Above this packing limit the onset of higher coordinated and more highly connected SiO and AlO units such as triply shared oxygen (TRI), returns the viscosity behavior to normal.

    This work helps us understand the distribution of melt viscosities at depth within the earth and other terrestrial planets.

    see highlight article here
  17. Measurements of liquid and glass structures using aerodynamic levitation and in-situ high energy x-ray and neutron scattering.

    Weber et al.J. Non. Cryst. Sol. 383 (2013)

  18. A time resolved high energy X-ray diffraction study of cooling liquid SiO2.

    Skinner et al. Phys. Chem. Chem. Phys. 15 (2013)
    X-ray diffraction patterns of molten silica were taken at 15Hz as it cooled from a laser heated liquid at 2000K to glass. From this, the Si-O bond length expansion/contraction was observed to change close to the glass transition / density minimum temperatures.

    Diffraction data download

  19. Structure and diffusion of ZnO–SrO–CaO–Na2O–SiO2 bioactive glasses: a combined high energy X-ray diffraction and molecular dynamics simulations study.

    Xiang et al. RSC Adv. 3 (2013)

  20. Benchmark oxygen-oxygen pair-distribution function of ambient water from x-ray diffraction measurements with a wide Q-range.

    Skinner et al. J. Chem. Phys. 138 (2013)
    High resolution pair distribution function measurements (gOO(r)) on ambient water were made. These measurements covered a wider reliable Q-range than previously achieved. This allowed precise determination of the 1st O-O peak height (see figure), and confirms that fine structural features previously observed were measurement artefacts. The pair distribution function measurement also includes error bounds.

    Diffraction data download

  21. The structure of liquid alumina: A joint diffraction and modeling approach.

    Skinner et al. Phys. Rev. B 87 (2013)
    Neutron and x-ray diffraction measurements were combined with simulation techniques to reveal the detailed structure of molten aluminium oxide at 2400K. The Al-O coordination of alumina was found to be 2/3 tetrahedral (blue in figure) and 1/3 five or six coordinated (green in figure). The 5- and 6-coordinated polyhedra were more likely to edge share than the tetrahedra, which were predominantly corner sharing. The higher coordinated polyhedra were found be fairly uniformly distributed, but had a slight preference for neighbors of the same coordination.

    The figure is a slice of the final diffraction-consistent structure model.

    Diffraction data download

  22. Structure of molten CaSiO3: Neutron diffraction isotope substitution and aerodynamic levitation study.

    Skinner et al. Phys Chem B 116 (2012)

  23. Structure of the floating water bridge and water in an electric field.

    Skinner et al. Proc. Nat. Acad. Sci. (USA) 109 (2012)
    The floating water bridge is a string-like connection of water formed under high electric fields (see figure). This phenomenon was investigated using high energy x-ray diffraction, including azimuthal analysis of the diffraction pattern.Only bulk water structure was observed, excluding molecular alignment as an explanation for bridge formation or stability. Structural changes observed were consistent with the elevated temperature of the water within the bridge (yellow in figure is approx. 320K).

    Diffraction data download
    See highlight articles here and here

  24. Comment on ‘Molecular arrangement in water: random but not quite.’

    Skinner et al. J. Phys. Condens. Matter 24 (2012)

  25. Structure and triclustering in Ba-Al-O glass.

    Skinner et al. Phys. Rev. B. 85 (2012)
    This novel Ba2Al6O11 glass has less than the two O per Al for a fully corner shared tetrahedral network to form. Instead the Al are found to remain fully tetrahedral, but save oxygen compared to more ordinary silicate glass networks by sharing O between three tetrahedra (triclusters). The figure shown is a slice of the final diffraction-consistent structure model, with triclusters highlighted by the red circles.

  26. Structural changes in vitreous GeSe4 under pressure.

    Skinner et al. J. Phys. Chem. C. 116 (2012)
    Synchrotron x-rays and diamond anvil pressure cells were combined to measure the structural changes in glassy GeSe4 under pressure up to 8.6GPa.The figure shows the measured x-ray pair distribution functions at 0, 1.5, 3, 4.3, 6, 7, and 8.6 GPa, the first peak fit, and fit - data patterns at 0 and 8.6 GPa. This shows that the closest bonds associated with the 1st peak don't change much, whilst the longer neighbours rearrange to form a more tightly packed structure.

    Diffraction data download

  27. Area detector corrections for high quality synchrotron X-ray structure factor measurements.

    Skinner et al. Nuc. Instrum. Meth. A 662 (2012)
    A series of correction procedures is illustrated for x-ray diffraction from area detectors. The figure right is structure factor data for glassy GeSe2 obtained in this work, compared to literature data (labelled Petkov).

  28. Barnes et al. reply.

    Barnes et al.Phys. Rev. Lett. 106 (2011)
  29. Nanostructure of Calcium Silicate Hydrates in Cements.

    Skinner et al. Phys. Rev. Lett. 104 (2010)
    Calcium silicate hydrate is the main constituent of cement paste, which holds concrete structures together. The production of this paste from calcium carboonate is responsible for 5-7% of man made CO2 output. In this paper we used x-ray diffraction and Reverse Monte Carlo modelling to find that C-S-H structure is consistent with relatively well-ordered nano-crystalline grains (see Figure), and not consistent with a more disordered glass-like structure.

    Diffraction data download
    See highlight articles here and here

  30. Liquid-Liquid Phase Transition in Supercooled Yttria-Alumina.

    Skinner et al. Phys. Rev. Lett. 103 (2009)

  31. Phase separation, crystallization and polyamorphism in the Y2O3-Al2O3 system.

    Skinner et al. J. Phys.: Condens. Matt. 20 (2008)
    Previously polyamorphism was reported in yttria-alumina melts and glasses (Aasland et al., Nature 369). This was mainly on the basis of inclusions of the same composition, but different density to the surrounding glass. A liquid-liquid transition was proposed to explain this (blue line labelled A in figure). In our paper only crystalline inclusions were observed in the glasses, no second glassy phase was observed. On cooling instead of a liquid-liquid transition, crystal nucleation events (red symbols) were observed around the expected liquid-liquid transition line.

    Later work (Greaves et al., Science 322) reports a liquid-liquid transition only at the 20mol% composition, and in a new higher temperature regime of 1788K (labelled B in the figure). The Greaves et al. observation is yet to be repeated or confirmed by independent researchers (as of 2013).

  32. An oscillating coil system for contactless electrical conductivity measurements of aerodynamically levitated melts.

    Skinner et al. Rev. Sci. Instrum. 77 (2006)
    The inductance and resistance of a coil was used to measure electrical conductivity of molten levitated samples, without touching them.To combat heat drift problems associated with this sensitive measurement a moving mechanism was built. This allowed constant recalibration of the empty coil resistance and inductance, enabling accurate measurements.

  33. Novel behavior and structure of new glasses of the type Ba-Al-O and Ba-Al-Ti-O produced by aerodynamic levitation and laser heating.

    Skinner et al. J. Phys.: Condens. Matt. 18 (2006)
    Ba-Al-O and Ba-Al-Ti-O glasses were made for the first time. Their structures were measured using synchrotron x-ray diffraction. The left half of the figure shows some of the glassy samples made. The right half shows the aerodynamic levitation technique used to make the glasses.

Thanks to my co-authors (no particular order): AC barnes, CJ Benmore, PJM Monteiro, PS Salmon, JKR Weber, B Shyam, JE Drewitt, Y Wang, T Sakamki, G Shen, C Park, Y Kono, Z Jing, T Yu, ML Rivers, SR Sutton, V Honkimaki, J Neuefeind,TO Farmer, HR Wenk, SR Chae, SK Tumber, D Jin, G Jennings, HE Fischer, L Hennet, W Crichton, S Antao, E Soignard, E Rissi, SA Amin, L Lazareva, L Santodonato, E Bychkov, A Bytchkov, JL Yarger, C Huang, LGM Pettersson, A Nilsson, D Schlesinger, JA Sellberg, TA McQueen, ND Loh, H Laksmono, R. G. Sierra, D Nordlund, CY Hampton,D Starodub, DP DePonte, M Beye, C Chen, AV Martin, A Barty, KT Wikfeldt, TM Weiss, J Feldkamp, MM Seibert, M Messerschmidt, GJ Williams, MJ Bogan, S Kohara, M Wilding, I Pozdnyakova, K Ohara, Y Xiang, J Du, AW Wren, DJ Boyd, MR Towler, JB Parise.

Thanks to the US Department of Energy: My work at Stony Brook is funded by the Materials Sciences and Engineering Division, Office of Basic Energy Sciences under grant number BES DE-FG02-09ER46650.
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