Colloidal Crystals Structure and Dynamics
Ivan Vartaniants
DESY, Hamburg, Germany National Research University, ‘MEPhI’, Moscow, Russia
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 1 DESY Coherent X-ray Scattering and Imaging Group at DESY
Present members: Former members: • S. Lazarev • I. Zaluzhnyy • A. Zozulya (now@PETRA III) • I. Besedin • M. Rose • A. Mancuso (now@XFEL) • P. Skopintsev • O. Gorobtsov • O. Yefanov (now@CFEL) • D. Dzhigaev • N. Mukharamova • R. Dronyak • J. Gulden (now@FH-Stralsund) • U. Lorenz (now@University of Potsdam) • A. Singer (now@UCSD) • R. Kurta (now@XFEL) • A. Shabalin (now@CFEL)
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 3 High resolution microscopy
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 4 High resolution electron microscopy
Atomic structure of the Au68 gold Atomic resolution imaging of nanoparticle determined by electron graphene microscopy.
M. Azubel, et al., Science 345, 909 (2014) A. Robertson and J. Warner, Nanoscale, (2013),5, 4079-4093
Simulated HREM images for GaN[0001]
From: Wikipedia
From: Web Images From: Web Images Can we develop x-ray microscope with atomic resolution? It does not work with conventional approach due to the lack of atomic resolution X-ray optics
Can coherent x-ray diffraction imaging be the way to go? What is Coherence?
Coherence is an ideal property of waves that enables stationary interference
Soap bubble wikipedia.org Whether X-rays are coherent waves?
Max von Laue Nobel Prize in Physics, 1914 W. Friedrich, P. Knipping, M. von Laue, Ann. Phys. (1913) 100 years later
LCLS FLASH
H. Chapman et al., A. Mancuso et al., Nature (2011) New J. Physics (2010) Coherence
LCLS
2 λ LL=λ /(2∆ λ) LT=( R/ 2 D)
Longitudinal Coherence Length Transverse Coherence Length
Als-Nielsen & McMorrow (2001) Coherence properties of 3rd generation synchrotron sources
I.A. Vartanyants & A. Singer “Coherence Properties of Third-Generation Synchrotron Sources and Free-Electron Lasers”, Chapter in: Handbook on Synchrotron Radiation and Free-Electron Lasers Coherent volume (PETRA III, E=12 keV)
LV LH LL Coh. Flux Raw Undulator 260 µm 40 µm 0.02 µm 6×1012 ph/s Low-β DCWe Si (111) expect 260 aboutµm two40 µm orders 0.5 of µm magnitude 1.8×1011 ph/s Lowmore-β coherent flux at diffraction limited Raw Undulator 280 µm sources10 µm 0.02 µm 7×1011 ph/s High-β DC Si (111) 280 µm 10 µm 0.5 µm 2×1010 ph/s High-β
LV
LL 13
LH Coherent X-ray Diffraction Imaging Lensless X-ray Microscopy
Partially Coherent Coherent
beam X-rays sample electrons CCD neutrons Diffraction Phase Optics: Limited Retrieval Microscope Coherent X-ray Diffraction Imaging in forward direction
Kinematical approximation:
= d −𝑖𝑖𝐪𝐪∙𝒓𝒓 𝐴𝐴 𝒒𝒒 � 𝜌𝜌 𝒓𝒓 𝑒𝑒 𝒓𝒓 qz=0
, = , , ( ) d d −𝑖𝑖 𝑞𝑞𝒙𝒙𝑥𝑥+𝑞𝑞𝒚𝒚𝑦𝑦 𝐴𝐴 𝑞𝑞𝒙𝒙 𝑞𝑞𝒚𝒚 � 𝜌𝜌 𝑥𝑥 𝑦𝑦 𝑧𝑧 𝑧𝑧𝑒𝑒 𝑥𝑥 𝑦𝑦 Mancuso et al. J. Biotechnol. 149 229 (2010) ( , ) = , , d 𝜌𝜌 𝑥𝑥 𝑦𝑦 𝑧𝑧 � 𝜌𝜌 𝑥𝑥 𝑦𝑦 𝑧𝑧 𝑧𝑧 Small-angle scattering CDI Inverse Fourier transform: Non-crystallographic samples 1 ( , ) = ( , ) ( ) d d Uniform distribution of (2 ) 𝑖𝑖 𝑞𝑞𝒙𝒙𝑥𝑥+𝑞𝑞𝒚𝒚𝑦𝑦 electron density 𝜌𝜌 𝑥𝑥 𝑦𝑦 𝑧𝑧 2 � 𝐴𝐴 𝑞𝑞𝑥𝑥 𝑞𝑞𝑦𝑦 𝑒𝑒 𝑞𝑞𝑥𝑥 𝑞𝑞𝑦𝑦 𝜋𝜋 Unfortunately, phases of A(qx,qy) are not known!!! Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 15 Phase retrieval
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 16 Iterative phase retrieval algorithm
FFT sk(x) Ak(q)
Real Space Constraints Reciprocal Space Constraints
s'k(x) A'k(q) FFT-1
Real space constraints: Reciprocal space constraint: use all a priori knowledge: Ak ( q ) → Iexp( q ) •finite support •positivity R.W.Gerchberg & W.O. Saxton, Optic (1972) 35, 237 •… J.R. Fienup, Appl Opt. (1982) 21, 2758 V. Elser, J. Opt. Soc. Am. A (2003) 20, 40 14 Example of reconstruction (O.Yefanov)
FFT-1
replace apply amplitudes support
FFT Bragg Coherent X-ray Diffraction Imaging (Bragg CXDI)
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 19 Coherent X-ray Diffraction Imaging Lensless X-ray Microscopy
CCD
Partially Coherent 2θB Coherent
beam X-rays sample electrons neutrons Diffraction Phase Optics: Limited Retrieval Microscope Coherent Scattering on Au Crystals
•4 micron Au nanocrystal •Coherent X-ray Diffraction •Measurement at APS sector 33-ID (UNICAT)
21 I. Robinson, I. Vartanyants, et al., PRL (2001), 87, 195505 Sensitivity to strain
= =
𝜑𝜑 𝒓𝒓 𝒌𝒌𝑓𝑓 − 𝒌𝒌𝑖𝑖 ∙ 𝒖𝒖 𝒓𝒓 𝑸𝑸 ∙ 𝒖𝒖 𝒓𝒓
Courtesy to I. Robinson Bragg CDI
Kinematical approximation:
= d ρ(r) – periodic electron density in crystal −𝑖𝑖𝐪𝐪∙𝒓𝒓 𝐴𝐴 𝒒𝒒 � 𝜌𝜌 𝒓𝒓 𝑒𝑒 𝒓𝒓 Phase, or Scattered amplitude near Bragg peak: Shape function: projected strain field in crystal: ( ) 1, = d = = ( ) 0, ℎ −𝑖𝑖𝒉𝒉∙𝒖𝒖 𝒓𝒓 −𝒊𝒊𝒊𝒊∙𝒓𝒓 ℎ 𝐹𝐹 𝒓𝒓 ∈ Ω 𝐴𝐴 𝑸𝑸 � 𝑠𝑠 𝒓𝒓 𝑒𝑒 𝑒𝑒 𝒓𝒓 𝑠𝑠 𝒓𝒓 � 𝜑𝜑 𝒓𝒓 𝒉𝒉 ∙ 𝒖𝒖 𝒓𝒓 𝜈𝜈 𝒓𝒓 ∉ Ω Fh – structure factor = q - h Crystallographic samples, 𝑸𝑸 uniform distribution of strain
I.A. Vartanyants & I.K. Robinson, JPCM 13, 10593 (2001);
I.A. Vartanyants & O.M. Yefanov, in the book:Ivan X Vartaniants-ray Diffraction | APS, Argonne, February Modern 3, 2016 | ExperimentalPage 23 Techniques. (2015), pp. 341-384. 3D mapping of a deformation field inside a nanocrystal
SEM
Diffraction patterns from Pb Strain field shown by color gradient nanocrystal measured around Resolution: 40÷50 nm (111) Bragg peak M. Pfeifer, et al., Nature, 442, 63 (2006), R. Harder, et al., PRB B 76, 115425 (2007). Coherent Diffractive Imaging
Mancuso et al. J. Biotechnol. 149 229 (2010) Pfeifer et al. Nature. 442 63 (2006)
Bragg CDI Small-angle scattering CDI Crystallographic samples Non-crystallographic samples Uniform strain field Uniform electron density Ivan Vartaniantsdistribution | APS, Argonne, February 3, in2016 | the Page 25 sample of the sample Coherent imaging with atomic resolution
J. Gulden, et al., ''Imaging of Nanocrystals with Atomic ResolutionIvan Vartaniants Using | APS, HighArgonne,- FebruaryEnergy 3, 2016 Coherent | Page 26 X- rays'', XRM-2010 Proceedings, AIP Conf. Proc. 1365, 42-45 (2011) Theory
If several Bragg peaks are measured simultaneously:
= d = ( ) ( ) ( ) −𝑖𝑖𝐪𝐪∙𝒓𝒓 𝐴𝐴 𝒒𝒒 � 𝜌𝜌 𝒓𝒓 𝑒𝑒 𝒓𝒓 𝐵𝐵 𝒒𝒒 ∙ 𝐹𝐹 𝒒𝒒 ∙ 𝜌𝜌∞ 𝒒𝒒 ⨂𝑠𝑠 𝒒𝒒 Here: B(q) – envelope function; (2 ) = ( ) F(q) – structure factor of a unit cell; 3 s(q) – FT of the shape function 𝜋𝜋 𝜌𝜌∞ 𝒒𝒒 � 𝛿𝛿 𝒒𝒒 − 𝒉𝒉 𝜈𝜈 ℎ Inverse Fourier transform of this relationship:
= ( ) ( ) ( )
𝜌𝜌 𝒓𝒓 𝑏𝑏 𝒓𝒓 ⨂𝜌𝜌𝑢𝑢𝑢𝑢 𝒓𝒓 ⨂ 𝜌𝜌∞ 𝒓𝒓 ∙ 𝑠𝑠 𝒓𝒓 Here: b(r) – FT of the envelope function B(q); = ; ρuc(r) – electron density of a unit cell; s(r) – shape function 𝜌𝜌∞=𝒓𝒓 �+ 𝛿𝛿 𝒓𝒓 −+𝑹𝑹𝑛𝑛 𝑛𝑛 𝑹𝑹𝑛𝑛 𝑛𝑛1𝒂𝒂1 𝑛𝑛2𝒂𝒂2 𝑛𝑛3𝒂𝒂3 I.A. Vartanyants & O.M. Yefanov, in the Ivanbook: Vartaniants X- ray | APS, Diffraction Argonne, February 3, 2016Modern | Page 27 Experimental Techniques. (2015), pp. 341-384. Theory
This electron density is peaking at the regular positions of
the unit cell due to the function ρ∞(r) and has an overall shape of the sample s(r). Most importantly, it contains the position of the atoms in the unit cell due to the reconstruction of the electron
density function of a unit cell ρuc(r). This means the following: If the continuous intensity distribution around several Bragg peaks will be measured simultaneously and phase retrieval methods will be applied to get the phase, then, in principle, the electron density with atomic resolution will be obtained.
I.A. Vartanyants & O.M. Yefanov, in the Ivanbook: Vartaniants X- ray | APS, Diffraction Argonne, February 3, 2016Modern | Page 28 Experimental Techniques. (2015), pp. 341-384. CXDI using high energy coherent X-rays
E=100 keV Reconstruction Model
J. Gulden, et al., ''Imaging of Nanocrystals with Atomic Resolution Using High-Energy Coherent X- rays'', XRM-2010 Proceedings, AIP Conf. Proc. 1365, 42-45 (2011) CXDI using high energy coherent X-rays
F=1012 photons F=1013 photons F=1014 photons F=1015 photons
Pd nanocrystal 10 nm size An excellent scientific goal for diffraction limited storage ring? First realization of these ideas with photonic (colloidal) crystals Photonic crystals
Photonic crystals in nature Artificial photonic crystals
Photonic band gap materials
https://www.theochem.kth.se/research/phot_crys Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 33 t/Photonic_Crystals.html Colloidal crystals grown by self-organization
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 34 Growth of the colloidal crystal film
Vertical deposition method
A B C = RHCP A B
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 35 J-M. Meijer, et. al. Langmuir (2012), 28, 7631−7638. Coherent x-ray imaging of defects in colloidal crystals
J. Gulden, et al., Phys. Rev. B 81, 224105 (2010) European Synchrotron Radiation Facility ESRF Measurements at azimuthal angle φ = 0°
4 m
Experimental conditions (ID06, ESRF): • Energy: E=14 keV • Pinhole size 6.9 μm • Sample detector distance: 3.96 m • Detector pixel size: 9 μm • Detector size: 4005×2671 pixels Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 38 J. Gulden, et al., Phys. Rev. B 81, 224105 (2010) Measurements at azimuthal angle φ = 0°
Diffraction pattern with Results of reconstruction from the subtracted pinhole this diffraction pattern
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 39 Measurements at azimuthal angle φ = 35°
Experimental conditions (ID06, ESRF): • Energy: E=14 keV • Pinhole size 6.9 μm • Sample detector distance: 3.96 m • Detector pixel size: 9 μm • Detector size: 4005×2671 pixels Measurements at azimuthal angle φ = 35°
Diffraction patternFor with the firstResults time of reconstruction from the subtracted pinhole this diffraction pattern defect coreStacking fault defect imaged was directly imaged using coherent Ivanx Vartaniants-rays | APS, Argonne, February 3, 2016 | Page 41 Extension to 3D
Crystallography with coherent X-rays
J. Gulden, et al., Optics Express, 20(4) 4039 (2012) A. Shabalin, et al., (2015)Ivan (inVartaniants preparation) | APS, Argonne, February 3, 2016 | Page 42 PETRA III Structural evolution of colloidal crystal films in the vicinity of the melting transition
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 44 Tuning of properties by external fields
Pumping energy Strain field engineering
Y. Y. Hui et al., ACS Nano 7 (8), 7126 (2013) Incremental heating
M. Daryl et al., PRL 108, 033902 (2012)
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 45 http://www.st-andrews.ac.uk/microphotonics/Gallery.php http://www.amolf.nl/research/nanooptics/news/detailpage/artikel/pumped-photonic-crystal-accelerates-slow-light/ Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 46 E. Sulyanova et al., Langmuir 31(19), 5274 (2015). Experimental setup. P10 beamline, PETRA III
B
A Colloidal crystal film Experimental conditions: • Energy: E=15 keV, 8 keV •Beam size 50x50 μm, 3.5x2.8 μm •Sample detector distance: 5.1 m • Detector pixel size: 55x55 μm2 A B • Detector size: 516×516 pixels
50 x 50 µm 3.5 x 2.8 µm
15 keV 8 keV Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 47 X-ray diffraction patterns measured in situ during incremental heating
Experiment A 15 keV, 50 x 50 µm unfocused beam
50 µm-1
50 µm-1
Experiment B 8 keV, 3.5 x 2.8 µm focused coherent beam
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 48 X-ray diffraction pattern of the experiment A measured at room temperature
X-ray diffraction pattern Same pattern with Enlarged area of (b) of the experiment A SAXS contribution showing Bragg peak measured at room subtracted. indexing. temperature.
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 49 Temperature evolution of the Bragg peaks parameters experiment A
T, K T, K Position of the Integrated Bragg peak intensity
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 50 Temperature evolution of the Bragg peaks parameters experiment A
T, K φ T, K FWHM of the Bragg q FWHM of the Bragg peak in radial peak in azimuthal Bragg peak direction, w direction, wq φ Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 51 Temperature evolution
Nano- scale Mesoscopic scale
Polysterene particle diameter D Lattice distortion parameter gq and average lattice parameter and domain misorientation
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 52 The model of colloidal crystal melting process
Nano- scale
Mesoscopic scale
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 53 The model of colloidal crystal melting process
Nano- scale
Mesoscopic scale
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 54 Free-electron lasers
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 55 We are living in exciting time !
FLASH at DESY LCLS at Stanford 2005 2009
Sometime Nobel prize in physics?
SACLA at Spring8Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 56 2011 European XFEL under construction (2016-2017)
European XFEL
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 57 58 Comparison of 3rd and 4th generation sources
X FEL
13 10 PhotonenPhotons
108!
1002-100 fs fs
9 Undulator 10 PhotonenPhotons (x 10 6 ) 100 ps
time
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 58 ENFMC 2012, Águas de Lindóia, 17.05.2012 Massimo Altarelli, European XFEL GmbH, Hamburg Study of dynamics in colloidal crystals
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 59 Observation and tuning of hypersonic bandgaps in colloidal crystals
> Polysterene spheres in air, glycerol, PDMS and silicon oil > = 256 , 307
> 𝐷𝐷Brillouin spectroscopy𝑛𝑛𝑛𝑛 𝑛𝑛𝑛𝑛 > No sintering
Brillouin light scattering spectra Supported opal and of dry and wet opals and scattering geometry phononic gap Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 60 W. Cheng et al., Nature Materials (2006) Pump-probe experiment on colloidal crystals at FLASH
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 61 Pump probe experiment on colloidal crystal film at FLASH > Study of colloidal crystal in the temporal domain Elastic vibration of the spheres (Lamb modes) Collective vibrations (phonons) Order-disorder transitions
Pump-probe experiment:
> Pump: 800 nm IR laser > Probe: 8 nm FEL radiation > Time delay from -100 ps up to 1000 ps, with 50 ps steps
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 62 R.Dronyak et. al., Phys Rev B 86 (2012) Pump-Probe Experiment on Colloidal Crystal Film at FLASH
Single-shot diffraction patterns at The momentum transfer vector Q different time delay and the horizontal Wx and vertical Wy size of the peaks were analyzed
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 63 R.Dronyak et. al., Phys Rev B 86 (2012) Pump-Probe Experiment on Colloidal Crystal Film at FLASH
Time dependence and power spectrum of |Q| for the selected 2/3(422) and 220 Bragg peaks
Theoretical calculations of vibrations of a 400 nm isotropic elastic sphere based on the Lamb theory reveal a 5.07 GHz eigenfrequency of the
ground (breathing) mode Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 64 Pump-probe experiment on colloidal crystals at LCLS
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 65 Experimental setup@XPP
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 66 Experimental setup@XPP
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 67 CSPAD detector
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 68 Experimental setup@XPP
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 69 Parameters of X-ray and IR laser beams
1. X-ray beam . E=8 keV . Pulse duration: ≤ 50 fs 9 . Fluxsample ~10 ph/pulse . Focus ~ 50 μm . Energy bandwidth ~10-4 X-ray beam
2. Laser beam • λlas = 800 nm Laser beam • Pulse duration: ≤ 50 fs • E ~ 2 mJ • Power: P ~ 4*1010 W • Focus ~ 100 μm
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 70 Pump-Probe experiment on colloidal crystals
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 71 Pump-Probe on Colloidal Crystals
Damage produced by laser powerIvan 7 Vartaniants° wave | APS, Argonne,plate February angle 3, 2016 | Page (~50 72 µJ) Study of ultrafast melting of colloidal crystals
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 73 Decay of integrated intensity of the peaks Decay of integrated intensity Diffraction pattern = 220 𝑜𝑜𝑜𝑜 𝑜𝑜𝑜𝑜𝑜𝑜 ∆𝐼𝐼 𝜏𝜏 𝐼𝐼1 𝜏𝜏 − 𝐼𝐼 𝑜𝑜𝑜𝑜𝑜𝑜 110 τ - time𝐼𝐼 delay between𝐼𝐼 laser and X-ray pulses 100 = 0 ∆𝐼𝐼 𝜏𝜏 𝜏𝜏 Fit of𝐼𝐼 integrated𝐴𝐴 ∙ 𝑒𝑒 intensity𝑒𝑒𝑒𝑒 − decay− with𝐴𝐴 exponential function𝜏𝜏
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 74 Time delays from -10 ps to +1000 ps Δτ=25.25 ps
Time delays from -10 ps to +250 ps Δτ=6.5 ps
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 75 Bragg peak’s broadening in q-direction
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 76 Bragg peak’s broadening in q-direction
q-direction
𝒘𝒘𝒒𝒒
- FWHM in q-direction
𝒘𝒘𝒒𝒒 ( ) - τ is time delay between laser = 𝑜𝑜𝑜𝑜 𝑜𝑜𝑜𝑜𝑜𝑜 𝑞𝑞1 𝑞𝑞 and X-ray pulses ∆𝑤𝑤𝑞𝑞 𝜏𝜏 𝑤𝑤 𝜏𝜏 − 𝑤𝑤 Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 77 𝑞𝑞 𝑜𝑜𝑜𝑜𝑜𝑜 𝑤𝑤 𝑤𝑤𝑞𝑞 Model of ultrafast melting of colloidal crystal
1. Energy transfer from IR laser to colloidal crystal?
2. Response of colloidal crystal lattice? a. Decay of Bragg peaks integrated intensity b. Growth of Bragg peaks FWHM
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 78 Model of ultrafast melting of colloidal crystal
Energy transfer from IR laser to colloidal crystal
• IR wavelength: 800 nm • Energy: 1.5 eV
• Energy of chemical bonds: (C-C, C-H) ~3-4 eV
• Absorption coefficient of 800 nm radiation in polystyrene: 10-4
• Temperature raise: one-two degrees
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 79 Model of ultrafast melting of colloidal crystal
Response of colloidal crystal lattice
In few 100 ps a Colloidal crystal is Upon cooling PS dry sintering of spheres are heated above Tg in PS spheres is frozen 50 fs going
Soft PS Dry sintering Liquid to solid spheres Ivan Vartaniants | APS,transition Argonne, February 3, 2016 | Page 80 Model of ultrafast melting of colloidal crystal
Response of colloidal crystal lattice
Colloidal crystal is In ≤50 ps a Upon cooling PS sintering of PS spheres are heated above Tg in 50 fs spheres is going frozen
Soft PS Sintering of Liquid to solid
spheres PS spheresIvan Vartaniants | APS,transition Argonne, February 3, 2016 | Page 81 Model of ultrafast melting of colloidal crystal
Response of colloidal crystal lattice
In few 100 ps In ≤50 ps a Colloidal crystal is PS dynamics is sintering of PS heated above Tg in damped spheres is going 50 fs (due to viscosity)
Soft PS Sintering of Liquid to solid
spheres PS spheresIvan Vartaniants | APS,transition Argonne, February 3, 2016 | Page 82 Variation of intensity and modulus of the scattering vector q as a function of packing density ρ
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 83 Model of ultrafast melting of colloidal crystal
This model explains decay of integrated intensity but does not explain the broadening of the Bragg peaks
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 84 Imperfections of the real colloidal crystal
The broadening of Bragg peaks can be explained by including the imperfections of the colloidal crystal lattice in the model
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 85 Model of ultrafast melting of colloidal crystal
Work in progress …
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 86 DESY future projects for large scale facilities
FLASH2020
PETRA IV
Courtesy to E. Weckert Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 87 PETRA IV: status and further development
5-th Diffraction Limited Storage Ring (DLSR) Workshop
DESY, 9-11 March 2016
Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 88 Acknowledgements
• DESY • E. Weckert • Former and present members of my group • P10 beamline (M. Sprung, A. Zozulya) • FLASH team • University of Utrecht • A. Petukhov • J.-M. Meijer • LCLS • XPP beamline • Russia • Institute of Crystallography RAS • RC “Kurchatov Institute” • National Research Nuclear Centre, “MEPhI” … • Ivan Vartaniants | APS, Argonne, February 3, 2016 | Page 89 We are looking for motivated PhD students and PostDocs Thank you for your attention!