Diffuse scattering - Laboratoire de Physique des Solides

frequentverseUrban and Civil

Nov 16, 2013 (3 years and 4 months ago)

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Crystallography and

Condensed matter




Initiated by the


«

Association Française de Cristallographie

»

(AFC)





Groups involved:



C. Lecomte, P. Fertey, S. Dahaoui

: Laboratoire de cristallographie et


de modélisation des matériaux minéraux et biologiques de
Nancy

(LCM3B)

J.
-
L. Hodeau
,
J.
-
F. Bérar
: Laboratoire de cristallographie de
Grenoble

H. Cailleau, E. Collet, Ph. Rabiller

: Groupe matière condensée et matériaux de
Rennes

E. Elkaïm, S. Rouzière

: LURE,
Orsay

D. Le Bolloc’h,

P. Launois, S. Ravy,

R. Moret
:

Physique des Solides,
Orsay

G. Calvarin, G. Baldinozzi
:

SPMS, Ecole Centrale
Paris

R. Caudron
:

ONERA
-
CNRS,
Châtillon


B. Capelle
: Laboratoire

de Minéralogie Cristallographie de
Paris

(LMCP)

F. Livet
: Laboratoire de Thermodynamique et Physico
-
Chimie Métallurgiques (LPTCM)



de
Grenoble

D. Grébille

: Laboratoire de cristallographie et sciences des matériaux de
Caen

(CRISMAT)




Philosophy of the project:


To provide the French community with a

consistent

state
-
of
-
the
-
art
diffraction techniques

platform

for chemistry, crystallography,

materials science and condensed matter physics.



Classical method
s

(extended to the newest developments):



Single crystal (periodic and aperiodic) and powders



Standard techniques and analysis tools



Different sample environments (T, P, E
, Laser
)






New methods

(SOLEIL 3
rd

generation source)

using:



Coherence



Brilliance



High resolution diffraction



Time
-
resolved diffraction




Stability
of the x
-
ray beam in position and intensity



Brilliance
of an undulator

ESRF




D2AM (bending magnet)



ID20 (magnetism)



ID1 (anomalous/surface)

Scientific case



Chemical bond and intermolecular interactions



Materials science



Electron density measurements



Element selective or contrast diffraction



Dynamics and out
-
of
-
equilibrium systems



Coherence and slow dynamics



ms to ns time
-
resolved x
-
ray crystallography



Ultra
-
fast time
-
resolved experiments



Phase transitions and local order



Materials science



No single crystals: require
powder
diffraction analysis



High angular resolution

needed (stress
-
strain analysis, lines separation)



Impact on industrial research



Pharmaceuticals, fine chemicals, metallurgy...




Electron density





Chemical bonding



Electrostatic potential, field, field gradient



Intermolecular interactions, charge transfer



Electronic pathways (catalysis)



Requires
precise data collection

(4
-
circle diffractometer)




Element selective or contrast diffraction



3
-
30 keV: K, L or M edges from K to U



Contrast enhancement (role of element in phase transition)



Solve complex structure (MAD, incommensurate)

Chemical bond and

Intermolecular interactions

Example: 4f electron density
modeling of rare earth
coordination compounds



Applications in materials science

(magnetism, Gd, medical imaging)



Model for actinides complex
es



(Nuclear waste cleaning )



Role of 4f electrons



Test of
ab initio

calculations (Density Functional Theory)



Need for high energy (25
-
30 keV)


Mn
-
Cu organo
-
metallic complex

Mn

Cu

Gradient of electron density

C. Lecomte et al.

Gradient path
:

Chemical bond

Atomic basins
:

Charge, multipole moment

Phase transition and local order I



Study of structural phase transitions



Determination of the structures involved



Structural change:
high resolution powder diffraction



Ex:

Reentrant
magneto
-
elastic transition

in HoFe
4
Ge
2


Evidence of subtle
structural distortion


accompanying

the magnetic phase
transition

Not visible in low resolution


Higher resolution

in SOLEIL

J. Rodriguez
-
Carvajal et al.

Line splitting



Mechanism of the Phase transition




Diffuse scattering

measurements:



Due to
critical fluctuations



Modeling of
microscopic interactions




Local Order




Diff
use scattering

due to defects and defects
-
induced deformations



Analysis of the spatial correlation functions


Ex:
Anomalous diffuse scattering
in Zirconia (Zr
-
YO
2
)

to disentangle Y and Zr contributions

Phase transition and local order II

k
-
l = 0

reciprocal

planes

20 eV below

Y K
-
edge

20 eV below

Zr K
-
edge

ESRF ID01 R. Caudron et al.



Diffuse scattering:



Weak effect (
high flux
)



Out
-
of
-
Bragg (
dedicated instrument
)


Dynamics and

Out
-
of
-
equilibrium systems

1 s

10
-
3

s

10
-
6
s

10
-
9

s

10
-
12

s

10
-
15

s



Study of photo
-
induced changes in:



Average structure, symmetry



Local order (diffuse scattering)



Photo
-
induced phase transformation



Coherence of the 3
rd
generation source:



X
-
ray Photo
-
Correlation Spectroscopy (XPCS)



Slow dynamics (study of speckle patterns)



Time
-
resolved intensity measurements

(not frequency measurements)



Pump
-
probe

technique



XPCS


X
-
ray Photo
-
Correlation
Spectroscopy

X
-
ray beam > coherence length:

statistical average

Speckle pattern



Measure of <I(t+t
0
)I(t
0
)>
t0
: X
-
ray Photo
-
correlation spectroscopy (XPCS)



Access to slow dynamics (10
-
3
-
100 s

) AND large scattering wave vector (10
-
3
-
10 Å
-
1
)



Successfully applied to soft matter physics (ESRF Troïka)

AuAgZn
2

F. Livet



Hard condensed matter:



Critical slowing down

close to phase transition



Domain motion

under external excitations



Charge
-
density waves under electric field



Ferroelectric domains



Effects of

impurities
on 2
nd

order phase transitions



Separation of
static and dynamics

effects

I(q)

Longitudinal coherence length: 1
m
m

Transverse

coherence length:
~
1
0

m
m

Pump
-
probe
experiment



Stroboscopic measurements



Pump: laser pulse (100 fs)



Probe: X
-
ray pulse (ESRF 50 ps, SOLEIL 30 ps)



Study of metastable states




Short lived (ms to ns) transient excited states



Time
-
resolved electron density measurements



Ex: Photo
-
induced spin transition

t

Pump

Probe

delay

Metastable state

Repetition rate (stroboscopy)

Ultrafast

ground state

Photo
-
induced phase transformation in ferroelectric TTF
-
CA

Neutral

Ionic/ferroelectric

D
+

A
-

D
+

A
-

2
1

Photo
-
induced long
-
range

ferroelectric order in 500 ps


Solid
-
Solid phase transformation


At shorter time scale ( < 10 ps)

1D exciton string formation


Time
-
resolved diffuse scattering !

ESRF ID9: E.Collet et al.

TTF

CA

Exciton



Study of mechanism

of phase transition
in time

instead of

temperature…


Ultra
-
fast

Time
-
resolved

Diffraction



Sub
-
picosecond phase transformation




Photoinduced electronic phase transformation




Measurements of time
-
resolved
Bragg scattering




Recent observation of Mott metal
-
insulator

phase transition at the sub
-
ps time
-
scale (VO
2

A. Cavarelli et al.)



Issue of
non
-
thermal ultra
-
fast phase transition




Photoinduced local order (charge transfer complexes)


Measurements of time
-
resolved
diffuse scattering

Need the creation of fs x
-
ray pulse in a dedicated undulator

Beyond

the scope of the beamline

Require the involvement of SOLEIL

27 m

36 m

Mono.

Beamline setup

U20 undulator

in short section

Optical

Hutch

Experimental

Hutch

Command
Room


Three
distinct

and
fixed

instruments




:
4
-
circle diffractometer (commercial)


Single crystals structure determination


:
6
-
circle diffractometer


Diffuse scattering, Coherence, Anomalous scattering


:
2
-
circle diffractometer


Powder diffraction

Source and

Optics

U20
undulator

10
17
2
3
4
5
6
7
10
18
2
3
4
5
6
7
10
19
2
3
4
5
6
7
10
20
Phot/s/0.1%bw/mm
2
/mr
2
2
3
4
5
6
7
8
9
10keV
2
3
4
5
Photon Energy
2

10

20

30 keV

10
20

10
19

10
18

10
17

Gap : 3.4
-
4 keV

K, Ca K
-
edge

Cd In L
-
edge

Optics not finalized yet...



Stability and coherence:



Classical 3:1 geometry



Commonly used (ESRF)



Short mirrors (coherence)

ID01

H: 388
m
m

V: 15
m
m

Crystallography and

Condensed matter




Initiated by the


«

Association Française de Cristallographie

»

(AFC)





Groups involved:



C. Lecomte, P. Fertey, S. Dahaoui

: Laboratoire de cristallographie et


de modélisation des matériaux minéraux et biologiques de
Nancy

(LCM3B)

J.
-
L. Hodeau
,
J.
-
F. Bérar
: Laboratoire de cristallographie de
Grenoble

H. Cailleau, E. Collet, Ph. Rabiller

: Groupe matière condensée et matériaux de
Rennes

E. Elkaïm, S. Rouzière

: LURE,
Orsay

D. Le Bolloc’h,

P. Launois, S. Ravy,

R. Moret
:

Physique des Solides,
Orsay

G. Calvarin, G. Baldinozzi
:

SPMS, Ecole Centrale
Paris

R. Caudron
:

ONERA
-
CNRS,
Châtillon


B. Capelle
: Laboratoire

de Minéralogie Cristallographie de
Paris

(LMCP)

F. Livet
: Laboratoire de Thermodynamique et Physico
-
Chimie Métallurgiques (LPTCM)



de
Grenoble

D. Grébille

: Laboratoire de cristallographie et sciences des matériaux de
Caen

(CRISMAT)







Source & Optics



Source


190 k


(2.5 MF


1.25 MF
SOLEIL

= 1.25 MF)


Mirrors


305 k



(2 MF)


Monochromator

230 k


(1.5 MF)


Other equipment

290 k


(1.9 MF)


(slits, flight tubes…)








1.015 M


(6.65 MF)




Infrastructure



Hutches, Fluids

380 k


(2.5 MF)







Experimental setups



4
-
circle


305 k



(2 MF)


2
-
circle


230 k



(1.5 MF)


N
-
circle


530 k



(3.5 MF)


Sample environments

155 k



(1 MF)


Detectors


350 k


(2.3 MF)





1.570 M


(10.3 MF)





-------------------------------------------------------------------




Total


2.965 M


(19.45 MF)




Estimated cost