Water
ice with LCLS-II
Probing Water
anddenser
other than
Liquids
Anders Nilsson, SUNCAT Ctr for Interface Science and Catalysis
Density of the liquid higher
than the solid
Normal liquid (ethanol, gasoline,etc)
Solid more dense than liquid
The Blue Planet
Access to Clean Water
The Challenge
for theChange
World with
Climate
Change
Climate
Water
Issues
Gore, Inconvenient Truth
Water denser than ice
Density of the liquid higher
than the solid
Normal liquid (ethanol, gasoline,etc)
Solid more dense than liquid
Density Maximum
Normal liquid
density
ddd
ddd
ddd
ddd
Water
Ssssssssssssssssssssssss
-50 -25 0 25 50 75
Temperature/ °C
At the bottom of the glass is 4 °C water
100
High Heat Capacity
It stabilizes the temperature in the Oceans
Ocean current stabilizes the climate
Anomalous Properties of Water
Isothermal
Compressibility
<(δV)2>=VkBTκT
Heat Capacity
Thermal
expansion
<(δS δV)>=VkBTα
<(δS)2>=NkBcp
Density fluctuations
Entropy fluctuations
Cross of density and
entropy fluctuations
Divergence towards a mysterious temperature of -45 °C
P. Kumar, S. Han, H.E. Stanley, J. Phys.: Condens. Matter 21 (2009) 504108.
X-ray Spectroscopies and Scattering Data
• XAS indicates predominant asymmetrical coordination with
fewer H-bonds than in tetrahedral model
Wernet et al., Science 304 (2004) 995
• XES shows two motifs: strongly tetrahedral
and very disordered
Tokushima et al., Chem. Phys. Lett. 460 (2008) 387
• SAXS shows fluctuating density inhomogeneity
Enhanced upon cooling
Huang et al., PNAS 106, 15214 (2009); 107, E45 (2010);
JCP 133, 134504 (2010)
•WAXS shows broad structural distributions
and shell-structure (~12 Å) consistent with
two structural motifs (and with SAXS)
Huang et al. Phys. Chem. Chem. Phys. 13, 19997 (2011)
Ice
Open spaces where no
molecules are present
If molecules move to fill the
open space there will be an
increase in the density
Summary room temperature to -20 °C
Strongly Distorted is related to local High Density Liquid (HDL)
Tetrahedral is related to local Low Density Liquid (LDL)
HDL and LDL fluctuations
Two local structural different motifs
≈1nm length scales at room temperature
Increasing length scale with decreasing temperature
A. Nilsson and L. G. M. Pettersson, Chem. Phys. 389, 1 (2011).
Snapshot from MD at -20 °C
Perspective on water
Chem. Phys. 389, 1 (2011).
Blue: High tetrahedrality
Yellow: High density
Box side length 100 Å
Probing bulk water and ice crystallization in "no-mans
land"; first results from the X-ray laser at Stanford
Congcong Huang, Trevor McQueen, Jonas Sellberg, Hartawan Laksmono, Duane Loh, Ray
Sierra, Christina Hampton, Dimitri Starodub, Dennis Nordlund, Martin Beye, Daniel Deponte1,
Andy Martin1, Andrew Barty1, Jan Feldkamp, Sebastian Boutet, Garth Williams, K. T. Wikfeldt2,
L. G. M. Pettersson2, Mike Bogan and Anders Nilsson
SLAC National Accelerator Center/Stanford University
1 Center for Free Electron Laser, Hamburg
2 Stockholm University
Single shot x-ray scattering
50 femtosecond pulse
Feb 2011
“No-Mans Land” below limit of homogeneous ice formation
Homogenous
Ice Nucleation
Limit -38 °C
ρ(HDA)=1.17 g/cm3
-45 °C in “no
mans land”
ρ(LDA)=0.94
ρ(Ih)=0.92
ρ(Ic)=0.92
High Density
Low Density
Amorphous Ice (LDA) Amorphous Ice
(HDA)
H. E. STANLEY “Mysteries of Water” Les Houches Lecture, May 1998
Originally Proposed P. H. Pool and H. E. Stanley et.al Nature 360, 324 (1992)
Different Models
Stability Limit
Retracing Spinodal
Liquid no longer stable
Ice is instantaneous formed -45 °C
R. J Speedy J. Phys. Chem. 86, 982 (1982)
A. C. Angell, Nature 331, 206 (1988)
2nd critical point model
HDL-LDL Liquid Transition
Widom line maximum HDL-LDL fluctuations -45 °C
P. H. Pool et al., Nature 360, 324 (1992)
Variation vid Critical Point at O K
S. Sastry et al., Phys. Rev. E 53 , 6144 (1996). )
X-ray Emission Spectroscopy
HDL
LDL
LDL
HDL
Probing population of HDL and LDL using XES
Experiment in October at SXR, collaboration with Wernet et al HZB
Probing water at higher pressures and glassy forms
Homogenous
Ice Nucleation
Limit -38 °C
ρ(HDA)=1.17 g/cm3
-45 °C in “no
mans land”
ρ(LDA)=0.94
ρ(Ih)=0.92
ρ(Ic)=0.92
High Density
Low Density
Amorphous Ice (LDA) Amorphous Ice
(HDA)
H. E. STANLEY “Mysteries of Water” Les Houches Lecture, May 1998
Originally Proposed P. H. Pool and H. E. Stanley et.al Nature 360, 324 (1992)
SAXS – Ambient to Supercooled Regime
At low Q range
S(Q) shows an
unusual enhancement
Much larger
enhancements
(fluctuations!)
at lower T
S A (Q ) ∝
1
ζ −2 + Q 2
Q<<1)
F.T.
gA(r)~exp(-r/ζ)/r (r>>1)
The isothermal compressibility χT
S (0) = k B Tnχ T
Very good fit to previous data
Huang et al., PNAS 106, 15214 (2009); PNAS 107, E45 (2010); JCP 133, 134504 (2010)
Apparent Power Law – Widom Line
Critical phenomena characterized by power laws with critical exponents
.32
2nd critical point scenario
Fluctuations between HDL/LDL
Poole et al., Nature 360, 324 (1992)
.52
Fit ζ to (apparent) powerlaw
ξ = ξ 0ε −ν
with
ε = T / Ts − 1
TIP4P-2005 simulations
Blue LDL Red HDL
based on inherent structure
Huang et al. JCP 133, 134504 (2010)
K. T. Wikfeldt et al. Phys. Chem. Chem. Phys, 13, 19918 (2011).
Probing correlation length in no-mans land
Widom Line
2nd critical point
T
P
ξ
We need much higher intensity !!!
T
Super hard x-ray diffraction study on water pair correlation function
APS 11-ID-C: 115 keV photons and an amorphous Silicon area detector
Current CXI
Fourier Transform
Long-range orderings
(up to 1.4 nm) are visible!
293 K
Courtesy C. Benmore
Disordered Structures
Nonequilibrium Phenomena
Transient States
Ordered Structures
Equilibrium Phenomena
1900
Era of Crystalline Matter
Era of Disordered Matter
Conventional X-ray Probes
Coherent X-ray Probes
2000
Courtesy of H. Dosch
future
„Laser Speckles“
Coherent Diffraction Pattern
obtained from frozen liquid (glass)
P. Wochner et al., PNAS 106, 11511 (2009)
Hidden Local Symmetries from
Higher-Order Correlation Functions
4-point correlations
CQ (∆) =
MPI-MF DESY ESRF
P. Wochner et al.
PNAS 106, 11511 (2009)
< I(Q, ϕ )I(Q, ϕ + ∆) >ϕ − < I(Q, ϕ ) >ϕ2
< I(Q, ϕ ) >ϕ2
Angular Correlations of H2O
Detector Position 1
Detector Position 2
Detector Position 3
97.5 mm
122.5 mm
147.5 mm
∆ (º)
∆ (º)
q (Å-1)
∆ (º)
Jan Feldkamp, Jonas Sellberg and Derek Mendez
Ultrafast XPCS using ‘Split Pulse’ Mode
Femtoseconds to nanoseconds time resolution
Uses high peak brilliance
splitter
Contrast
transversely coherent
X-ray pulse from FEL
sample
variable delay
Analyze contrast
as f(delay time)
sum of speckle patterns
from prompt and delayed pulses
recorded on CCD
Bonds vs. Entropy
localized bonds
delocalized
bonds
Bond Energy
Entropy
Pump-probe
Perform pump-probe
IR-THz and x-ray
IR spectra
Probe stability and dynamics of
HDL and LDL structures
Selective excitations in libration band
Probe XES, SAXS, CXI
Water
Ice
Frustrated Motion in H-bonds
From Y. Maréchal, The Hydrogen Bond and the
Water Molecule, Elsevier (2007)
Water and Biology
Hydration layer in DNA and Proteins
Interfacial Water
Wish list LCLS II
• High Intensity (>10 mJ) small focus for CXI experiments
• Higher Energy 30-100 keV for large Q space (3rd harmonics)
• Detector with a uniform response
• X-ray correlation spectroscopy from 100fs to ms
• THz – IR pump
• Soft x-ray dedicated liquid endstation
• Stimulated emission
• Different sample geometries, high pressure with a pulse source
• End station for surfaces and interfaces, both soft and hard x-rays