“Probing materials at ILL: an overview of structure investigation with neutrons”

1. Probing
materials
at
ILL:
an
overview
of
structure
inves7ga7on
with
neutrons
Viviana
CRISTIGLIO
Instrument
Scien6st
at
the
Ins6tut
Laue
Langevin
-­‐
Neutrons
science
at
high
T
-­‐
Carbon
nanotubes
-­‐
Li
ba=eries
Industrial
materials,
Energy

2. The
liquid
state
is
fundament
state
of
the
ma=er
and
is
an
essen6al
stage
for
various
technological
applica1ons
Metallurgy
Op6c
fibers
Aerospace
propulsion
Why
do
we
need
HT?
Glass
making
:
from
liquid
to
glass
by
quenching
Design
of
new
glasses
:
Storing
nuclear
waste
Food
and
drink
Chemistry,
Pharmaceu6cs,
Cosme6cs

3. Structure
of
Liquids
by
diffrac6on
Unlike
crystals,
the
structural
informa6on
for
liquids
and
glasses
is
described
in
terms
of:
1. Probabilis6c
atomic
distribu6on
func6ons.
2. Mean
atomic
distribu6on
around
each
chemical
species
given
by
the
Pair
Distribu6on
Func6on
g(r).
g(r)
is
the
probability
to
find
an
atom
at
a
distance
r
from
another
taken
at
the
origin
Interatomic
distances
Coordina6on
number

4. Spa6al
distribu6on
of
atoms
or
molecules
in
the
system
Crystalline
solids
Equilibrium
posi6ons
Well
defined
Bragg
peaks
Amorphous
Distribu6on
of
equilibrium
posi6ons
No
Bragg
peaks
Structure of Crystalline and Amorphous Solids

5. Diffusive
Mo6ons
Internal
Dynamics
Structural
informa7on
Collec6ve
dynamics
Coherent
σcoh
4π
Incoherent
σinc
4π
Sca=ering
cross
sec6on
σ
=
σcoh
+
σinc
Coherent
and
Incoherent
ScaAering

6. More
sensi6ve
to
light
elements
(H,
Li,
Bo)
But
Isotopic
subs6tu6on
()
H/D
exchange
Complexity
in
the
data
interpreta6on
à Mul6-­‐techniques
approach
Why
neutrons
are
useful
for
liquids?
neutrons
X-­‐rays
Bragg law

7. Radioactive waste disposal

8. Aqueous Solutions in Confined Systems
Underground
Research
Laboratory
at
Meuse
Haute-­‐Marne,
ANDRA,
French
Na6onal
Agency
for
the
Management
of
Radioac6ve
Waste
Clays have wide environmental applications,
but particularly in waste disposal
Radioactive waste disposal

9. SiO2
(Network
former)
Si-­‐O
Strong
bond
Al2O3
(Intermediate
element)
Ca/Mg/Na-­‐O
(Network
modifier)
Al-­‐O
Less
strong
bond
+
+
4
Bridging
oxygens
3
Bridging
oxygens
Strong
liquid
Fragile
liquid
Alumino-­‐silicates
Ca/Mg/Na
-­‐
Al2O3
-­‐
SiO2

10. Alumino-­‐silicates
Ca/Mg/Na
-­‐
Al2O3
-­‐
SiO2
©
Britannica
©
D.
Neuville
Etna,
Sicily
Crust
and
mantle
forma6on,
magma6c
ocean
Candidate
for
waste
storage
New
class
of
cements

11. ü Maintain
the
purity
of
the
sample
ü Access
very
high
temperatures
(>
3000°C)
ü Absence
of
heterogeneous
nuclea6on
ü Easy
access
to
metastable
states
ü Undercooling
(Several
hundreds
degrees
below
the
mel6ng
point)
Aerodynamic
levita7on

12. r (Å)
g(r)
Glass
Ca-­‐O
correla6on
less
pronounced
Difficult
to
solve
the
Ca-­‐O
because
its
mostly
composed
by
O-­‐O
(50%of
the
total
g(r))
Molecular
dynamics
model
for
experimental
data
interpreta6on
Ca-­‐O
Liquid
r (Å)
Pair
Distribu6on
Func6on:
From
Molecular
Dynamics
calcula6ons
Liquid
CA
(SiO2
=
0)

13. Diffusion
coefficient:
D
[10-­‐10
m2s-­‐1]
1000/T
[K]
Arrhenius
plot
1-­‐
Si
atoms
have
a
lower
self
diffusion
2-­‐
Si
SiO4
tetrahedra
O,
Ca
Dcoherent
When
SiO2

14. Introduc6on
Instrumenta6on
Structure
Dynamic
Conclusion
• QENS
setup
• Mul6-­‐nozzle
Aero.
Lev.
• Benefits
• Objec6ves
• Glassy
state
• Liquid
state
• QENS
• IXS
What
is
the
common
point
between:
Volcanic
lava,
Magma,
Silicate
melt,
Glass
?
• Amorphous
material
• Disordered
at
the
atomic
length
scale
• Very
high
temperature
• SiO2
-­‐
Al2O3
-­‐
CaO
How
the
viscosity
of
a
volcanic
lava
changes
with
temperature?
With
its
chemical
composi6on?
©
Britannica
©
Britannica
©
D.
Neuville
Etna,
Sicily
The liquid state is also an essential stage for
various technological applications:
Metallurgy
Op6c
fibers
• Design
of
new
glasses
(storing
nuclear
waste,…)
Applica6ons
Aerospace
propulsion
3
Crust
and
mantle
forma6on,
magma6c
ocean

15. Calcium
AluminoSilicate
(CAS)
SiO2
(Network
former)
Tetrahedral
Si-­‐O
Strong
bond
Al2O3
(Intermediate
element)
CaO
(Network
modifier)
Tetrahedral
Al-­‐O
Less
strong
bond
>>
+
+
4
Bridging
oxygens
3
Bridging
oxygens
Strong
liquid
Fragile
liquid
4
Introduc6on
Instrumenta6on
Structure
Dynamic
Conclusion
• QENS
setup
• Mul6-­‐nozzle
Aero.
Lev.
• Benefits
• Objec6ves
• Glassy
state
• Liquid
state
• QENS
• IXS

16. Objec6ves
of
this
thesis
(1)
Two
furnaces,
same
principle!
• High
temperatures
• Silicate
Melts
Important
to
be
able
to
study
the
proper6es
of
high
temperature
liquids:
First
objec1ve
of
this
thesis:
Develop
and
Combine
different
techniques
on
large
scale
instruments
in
order
to
study
the
structure
and
dynamics
of
high
temperature
liquids.
ESRF
ILL
5
Introduc6on
Instrumenta6on
Structure
Dynamic
Conclusion
• QENS
setup
• Mul6-­‐nozzle
Aero.
Lev.
• Benefits
• Objec6ves
• Glassy
state
• Liquid
state
• QENS
• IXS

17. Objec6ves
of
this
thesis
(2)
Monitor
the
evolu1on
of
viscosity
η
Study
the
dynamics
Neutron
and
X-­‐ray
Inelas6c
Sca=ering
Angell
Plot
Study
the
structure
(Neutron
and
X-­‐ray
Diffrac6on)
The microscopic mechanisms approaching
the glass transition are still not well
understood:
Rapid
change
in
the
dynamical
proper6es
like
the
viscosité
(
η
)
Correlate
Structure
and
Dynamics?
Add
strong
glass
former
“SiO2”
+
6
Introduc6on
Instrumenta6on
Structure
Dynamic
Conclusion
• QENS
setup
• Mul6-­‐nozzle
Aero.
Lev.
• Benefits
• Objec6ves
• Glassy
state
• Liquid
state
• QENS
• IXS

18. The
common
principle
is
to
apply
a
force
to
counteract
the
gravity
G
F
Various
levita7on
techniques
have
been
developed
Levita7on
techniques
Electromagne6c
field
Electrosta6c
field
Acous6c
wave
Gas
flow
Gas
film
levita6on
Aerodynamic
levita1on
Possible
to
reach
very
high
liquid
temperatures
(>3000°C)
No
container
effect
These
methods
maintain
the
sample
purity
Easy
access
to
the
supercooled
state
Advantages
:
(few
hundred
degrees
below
the
mel6ng
point)

19. Limita6ons
for
QENS
X-­‐rays:
Diffrac6on
Inelas6c
Sca=ering
o
Flux
of
X-­‐ray
>>
Flux
of
Neutrons
o
Current
configura6on:
Half
of
the
sample
is
s6ll
masked
by
the
nozzle.
Neutrons:
Diffrac6on
Inelas6c
Sca=ering
1.
Bigger
diameter
2.
Levitated
completely
outside
the
nozzle
Sample:
Diameter
∼
2.7
mm
9
Introduc6on
Instrumenta6on
Structure
Dynamic
Conclusion
• QENS
setup
• Mul6-­‐nozzle
Aero.
Lev.
• Benefits
• Objec6ves
• Glassy
state
• Liquid
state
• QENS
• IXS