d2am, from saxs to dafs. · equivalent esrf review committees : hs, me, sc (ch, in) commissioning,...
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D2AM,
a multipurpose anomalous beamline
from SAXS to DAFS.
BM2 presentationESRF
Science Advisory CommitteeNov. 7th, 2003.
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 1 of 19
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Summary.
• D2AM : a French CRG at ESRF 3
• BM2 optics 5
• Science with the SAXS camera 6
• Science using the 7 circle goniometer 10
• Instrument improvement and detector development 15
• Perspectives 17
Diffraction Diffusion Anomale Multi longueurs d’onde(Anomalous Diffraction and Diffusion at Many wavelength)
A GRG/F beamline located on BM2 at ESRF
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 2 of 19
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D2AM : a French CRG at ESRF• A CEA and CNRS beamline for materials science and
biocrystallography, project leaders : J.P. Simon and M. Roth.
• Shared between both communities up to Feb 98.
• Operation since Sept. 94, reviewed in May 97.
• Beamtime delivered to users by review committees
year shifts proposals
ESRF CRG ESRF CRG
2001 132 342 10 32
2002 132 285 11 28
2003 131+15 279 11 25
RequestedAllocated ≈ 2.5
Teaching ≈ (5 days/year)
• equivalent ESRF review committees : HS, ME, SC (CH, IN)
• Commissioning, maintenance and in house research share the remaining time.
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 3 of 19
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A locally supported CRG.
The beamline activities are supported by 4 laboratories in Grenoble :
LTPCMINPG
LSPUJF
SP2MCEA
F Livet
JL HodeauJM Tonnerre
E Dooryhee
H Renevier
C Rochas
F Bley
E Geissler
JP SimonM de Boissieu
SAXSGONIO
CNRSLdC
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B CaillotS Arnaud
N BoudetJF BerarSUPPORT
METALS SCATTERING
DIFFRACTION
SOFT MATTERSTRUCTUREDINTERFACE
≈ 10 researchers participate inthe activity and local contacts,
• 4 people work on beamline(scientists, engineer and tech-nician).
→ In-house research is shared between these labs.
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 4 of 19
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BM2 optics :dedicated to anomalous measurement with low parasitic scattering
• 5 - 25 keV ≈ : Cr K-edge → Pd K-edge Ti and I edges already used
• Resolution ∆E/E ≈ 10−4 Si(111) High harmonic rejection
• Beam size used in the monochromator : V = 1→ 4 mm,H = 1→ 30 mm.
• 2.1011 photons/s in a 0.3× 0.3 mm2 spot at sample position.
• very stable optics : coherent measurements over 24h have been performed, nofeed-back
J. Synchrotron Rad. 1998, 5 1346-1356 J.L. Ferrer et al.
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 5 of 19
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SAXS Experiments on BM2.
Q ≈ 5.10−4A−1 → 2A−1 E ≈ 6→ 20 keV
2D collection in USAXS cover the range of visible light scattering
J. Applied Cryst. 1997, 30 900-904 J.P. Simon et al.
• Anomalous SAXS : from metallic alloys → polyelectrolyte gels.Macromolecular Symposia 2003, 200 2227 I. Morfin et al. (LSP)
• in situ SAXS : metallic alloys and polymers
• X-ray Photon Correlation Spectroscopy
• USAXS
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 6 of 19
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In-Situ SAXS measurements
of precipitation hardening in Aluminium alloys.
Evolution of the volume fraction and particle size in in-situ experiments at 20oC/min.
The best hardened sample ( ≈ 15h 140oC ) shows 2 steps during heating.
In an over-aged sample ( ≈ 6h 170oC ) it is difficult to favor one of these steps.
Validation of thermodynamic models for precipitation
in the heat affected zone of welds.
Acta Materiala 2003, in press M. Nicolas et al. (LTPCM)
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 7 of 19
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Structural relaxation after stirring a silica filler
in a polymer melt.
(coherent) X-ray intensity correlation func-
tions G(t) of fume silica samples.
+ untreated in PDMS melt (liquid),
o hydrophobic surface-treated in PDMS melt,
• dry
Analysis of data reveals
diffusion controlled structural
relaxation
Γ = Dq2(1+a exp (−Dsq2to))
Ds = 10−15cm2/s
This shows storage life time of uncross-linked polymer-filler mixtures, e.g. in themanufacture of automobile tyres : floccu-lation of filler particles have to be avoidedto preserve elasticity.
Phys. Rev E 2000, 62 8308 E. Geissler et al. (LSP)
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 8 of 19
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USAXS in filled polymers.Scattering pattern from polyethylene filled with N330 carbon black
Horizontal, vertical span of figures : −4.10−3A−1 ≤ q ≤ 4.10−3A−1
cast from solution melt blended
Anisotropy from residual strains, seen at q ≤ 10−3A−1 defines the local Poisson ratio
σ found from the positions of the maxima qK in a Kratky plot.
Langmuir 2001, 17 329 F. Ehrburger-Dolle et al. (LSP)
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 9 of 19
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Science using the 7 circle goniometer.• Amorphous and liquids
Levitated laser-heated
Y2O3 melting behaviour
Europhys. Lett. 1998, 44 4 C. Landron et al.
Applied Phys. Lett. 2003, 83, 3305 L. Hennet et al.
• Diffuse scattering : Direct Evidence of Lattice-relaxed Charge-transfer
Exciton-string Europhys. Lett. 2002, 57, 67 E. Collet et al.
• Structural evidence of Ta tetramerization displacement in the charge
density wave compound (TaSe4)2I.
(1 0 13) reflection and its
8 satellites with 3 orders.
Only the upper ones exhibit
a strong anomalous variation
at Ta LIII edge.
Phys. Rev. Lett. 2001, 87 15502 V. Favre-Nicolin et al. (LdC)
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 10 of 19
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Elastic constants of i-AlPdMn quasicrystalsLong phason fluctuations : characteristic of quasiperiodic long range order.
Gives rise to diffuse scattering (similar to thermal diffuse scattering)
Absolute scale measurement :
• allows determination of the pha-
son elastic constants,
• comparison with models and
other phases.
Phil. Mag. Lett. 2001, 81 273-283
J. Alloys and Compounds. 2002, 342
265-270
M. de Boissieu et al. (LTPCM)
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 11 of 19
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Anomalous diffraction.Single crystal → Multi layers → Powders
As an example, it allows the localisation of cations in bicationic zeolite which arepromising for enhancement of difficult separation processes.
The anomalous contrast and the data quality allow the site occupied by fewcations to be differentiated from water in Fourier maps.
J.L. Hodeau E.C.M. Durban 2003 (LdC)
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 12 of 19
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Diffraction Anomalous Fine Structure at BM2Energy-scan diffraction needs both spectroscopic and diffraction requirements to be
satisfied → specific developments.
Photodiode-based moni-
tor + detector : low noise
and high dynamic range.
Quick DAFS
(006) InAsP thin film :
1keV recorded in 4min at
Ga K-edge
Peak measurements with
rocking-sample holder and
feedback control
J. Synchrotron Rad. 2003, 10 435-444 H. Renevier et al. (LdC, CEA)
Charge ordering and forbidden reflections in Magnetite
Phys. Rev. Lett. 2000, 10 435-444 J. Garcia et al. (in collaboration with LdC)
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 13 of 19
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InAs / InP Quantum Wires.• Quantum size effect : materials for opto-electronic (lasers,...)
• Self-organized 2D growth driven by anisotropic strain at the interface
InAs/InP QWrs without capping
∆a/aInP = −3.3% [110] relaxed
λ ≈ 20 nm, height = 0.6 − 2.2 nm [1-1 0] InP matched
local structure of InAs QWrs by means of GI-DAFSEuroPhys. Lett. 2002, 57 499 S. Grenier et al. (LdC, CEA)
next : Buried InAs/InP QWrs
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 14 of 19
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Instrument improvement and detector development• Sample environment : in-situ attachments, furnace, cryostat...
• motion control move from MicroControle → ESRF VPAP⇒ improvement in reliability (2002-2003)⇒ non linear motion used in Quick DAFS (2001)
• full vacuum path to goniometer center achieved in 2002⇒ lower parasitic scattering + higher flux at low energies ( below Fe edge)
• focussing : 0.3× 0.15 mm2 now achievable→ sagittal bender → CNRS-ESRF design (1998-1999) ⇒ reproducibility→ mirror bender modified
• improvement of detectors→ high speed 1D gas detector→ Fiber Optic coupled CCD introduced in 1997-98→ new Princeton FO-CCD since 2002→ pixel detector development since 1997
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 15 of 19
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Pixel detectorCurrently available detectors are far below the source performance, we are developing
together with the CPPM-IN2P3 new detectors using hybrid microelectronic technology:
prototype pixel size 300× 300 µm2
energy range : 10→ 25 keV ∆E ≈ 1.5 keV
dead time τ ≈ 0.2.10−7s 31 bit counters
exposure 1 ms → 1000 s + 2 ms (read-time)
kinetics 200− 400frames
linearity
from
0.01photon/s/pixel
up to
2.106photon/s/pixel
Direct evidence of diffuse scattering
near quasicrystal Bragg peaks.
prototype at BM2 SAXS station
and modules before assembly
J. Appl. Cryst. 2002, 35 471 J.F. Berar et al. (LdC)
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 16 of 19
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Perspectives.Optics was delivered in 94, it must be improved to preserve the quality of theincoming beam.
• Mirrors :
– Roughness → Diffuse scattering.
– Complex structure in the vertical plane of the beam.
• Mono :
– Sagittal focussing → reduce some aberrations.
– Coupling between tuning and rotation → need to reoptimize the tuningduring Energy scan : waste of time/fiability in DAFS experiment.
Instruments have to be modified to follow the emergence of new materials
• The geometry of the goniometer has to be modified to favor DAFS studiesin grazing incidence (GI-DAFS).
• The hutch has to be modified to allow the use of a longer SAXS station.
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 17 of 19
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Perspectives.
Improvment of instruments and the signal/noise ratio to access to
→ anomalous mapping of layered materials (GONIOMETER).
→ local structure of new structured layers (GI-DAFS).
→ weak scattering solutions (radiation sensitive samples) (SAXS).
Ferroelectric PbZrTiO3 dots
size = 80− 100 nm
spacing = 300 nm
coverage area = 0.4× 0.4 mm2.
Their diffraction image is a non destructive analysing tool.
CCD / Counter
Pixel detector will allow to reach on 2D the needed data quality.
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 18 of 19
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Thanks for your attention
• and to all those working to improve BM2 (local contacts...)
• and to our users for their results and suggestions
• and to the CRG office
• and to my colleagues working on the beamline,without them no experiment could be done.
jf Berar BM2 presentation at ESRF SAC, Nov. 7th, 2003 page 19 of 19