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Brillouin Scattering With Simultaneous X-Ray Diffraction at GSECARS, Advanced Photon Source: Toward Determination of Absolute Pressure Scales. Jay Bass 1 Stanislav Sinogeikin 1,2 Dmitry Lakshtanov 1 Carmen Sanchez-Valle 1 Vitali Prakapenka 2, Guoyin Shen 2,3 Jean-Philippe Perrillat 1 - PowerPoint PPT Presentation
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Brillouin Scattering With Simultaneous X-Ray Diffraction at GSECARS, Advanced Photon Source: Toward Determination of Absolute Pressure Scales
Jay Bass1
Stanislav Sinogeikin1,2
Dmitry Lakshtanov1
Carmen Sanchez-Valle1
Vitali Prakapenka2,
Guoyin Shen2,3
Jean-Philippe Perrillat1
Jingyun Wang1
Bin Chen1
1 University of Illinois at UC, Geology Dept. 2 GSECARS, The University of Chicago3 HPCAT, Advanced Photon Sourse, Argonne National Laboratory4 Carnegie Institution of Washington, Geophysical Laboratory
Fall AGU 2006
Isothermal bulk modulus (volume measurements)
Adiabatic elastic moduli(velocity measurements)
P K (V )
VVo
V dV
K VdP
dV
2
SV
K VP2 (4 /3)VP
2
Brillouin Scattering with synchrotron X-rays at the APS
Elasticity Grand ChallengeCOMPRES Infrastructure Development Project
Measure sound velocities and density simultaneously
“Absolute” or internally consistent Pressure ScalesZha et al., Brillouin on MgO (PNAS, 2000)
Phase Transitions: Stishovite - CaCl2
Stishovite - CaCl2 : Brillouin scattering velocities
Brillouin scattering Acoustic waves present in a solid due to thermal motion of atoms
Laser light interacts with phonons (or density / refractive index fluctuations) and is scattered with Doppler shifted frequency
Brillouin shift is proportional to acoustic velocity
Vi = / 2n*sin (/2)
Laser
O rig inalfrequency
Severa lfrequencies
Analyser
Frequency
O rig ina lB rillou insh ifted,Vp or Vs
Laserbeam IN
Scattered Light OUT
q
Vi = / 2sin (*/2)
Platelet (symmetric) geometry
Schematic diagram of the Brillouin system installed at sector 13-BMD (GSECARS) at APS
Sinogeikin et al.,Rev.Sci. Instr. 77, 2006
Schematic diagram of the Brillouin system installed at sector 13-BMD at APS (Lower Tier)
Motorized translation components (controllable from outside the hatch, blue boxes): HMTS - horizontal motorized translation stage; VMTS - vertical motorized translation stage; MLFA - motorized laser focusing assembly; MSCA - motorized signal collecting assembly; SPOA - sample positioning and orientation assembly; SL-LB - sample light / light block.
Observation / feedback elements (red boxes): VC - video camera; BT - beam target.X-ray components: MAR - MAR Imaging plate; XBS - X-ray beam stop; CS - cleanup slit.
Mobile focusing/collecting part of the Brillouin system at 13-BMD GSECARS
X-ray image and integrated spectrum of single-crystal NaCl at ambient conditions
Single crystal NaCl (B1) at ~30 GPa in DAC in Ne pressure medium
Au+Pt+NaCl
NaClSinglecrystal
Ruby
100 μm Au+Pt+NaCl
Schematic view of simultaneous Brillouin scattering and X-ray diffraction in DAC
X-ray image and spectrum of single-crystal NaCl in Ne at 30 GPa
NaCl (B1)(200)
Ne
Single crystal Brillouin spectrum of NaCl (B1) and velocity distribution in (100) plane at 30.5 GPa
-15 -10 -5 0 5 10 15Velocity, km /s
Inte
nsity
N aC l, 30.5 G Pa[110] d irection
D iam ondV S
D iam ondV S
NaClVP
NaClVP
NaClVS
NaClVS
N eBS
0 30 60 90 120 150 180
0.0
2.0
4.0
6.0
8.0
10.0
Vel
ocity
, km
/s[100]
C 11= 313.1 (2 .0) G PaC 44= 9.1 (1 .0) G paC 12= 64.5 (1 .5) G Pa
NaCl (B1), 30.5 GPa
[110]
2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4
D ensity
0
50
100
150
200
250
300
350
Cij's
, GP
a
C 11
C 12
C 44
2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4D ensity
0
50
100
150
Isot
ropi
c m
odul
i, G
Pa
K S
H SH S+
H S-
K S=(C 11+2C 12)/3H ashin-Shtrikm an bounds
Single crystal and aggregate elastic moduli of NaCl (B1) as a function of density
0 10 20 30Pressure, G Pa
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
Ani
sotr
opy
fact
or
M gO
N aC l (B1)
A=(2C44+C12)/C11-1
Anisotropy of NaCl (B1) to 30 GPa
0.0
2.0
4.0
6.0
8.0
10.0
Vel
ocity
, km
/sVs [100]
Vs [110]
Vp [110]
0 10 20 30Pressure
Vp [100]
2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4D ensity
2
3
3
4
4
5
Vs,
km
/s
H ashin-Shtrikm anVoigt-R euss-H ill
V S
2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4D ensity
4
5
6
7
8
Vp,
km
/s
H ashin-Shtrikm anVoigt-R euss-H ill
V P
Aggregate velocities of NaCl (B1) as a function of density
“Absolute” equations of state / pressure scale
Isothermal bulk modulus (volume measurements)
Adiabatic elastic moduli (velocity measurements)
dVV
VKP
V
Vo
T)(
TT dV
dPVK
3/)2( 1211 CCKS
2SV
22 )3/4( PPS VVK
)1( TKK TS
We measure Ks as a function of volume directly. The problem is to convert KS to
KT at high pressure, e.g. we need to know volume dependence of and .Possible models/assumptions:
constK T
V
V
00
?1;0
0
q
V
Vq
Conclusions
We simultaneously measured single crystal (and aggregate) elastic moduli of NaCl (B1) with Brillouin spectroscopy and density with angle dispersive X-ray diffraction to 30.5 GPa.
At high pressure NaCl exhibits extreme elastic anisotropy, which is >3 times higher than that at ambient conditions.
Above ~17 GPa on approaching B1-B2 phase transition NaCl exhibits acoustic mode softening.
Above ~17 GPa the density – velocity relations deviate from linearity and violate Birch’s law.
Acoustic softening indicates that B1-B2 phase transition in NaCl may be multi-step and of more complicated nature than it was previously thought.
Pressure calculated from measured bulk modulus and density is higher than that calculated from Decker EOS by ~ 3-5% at 30 GPa.
Acknowledgments• NSF: Elasticity Grand Challenge
• COMPRES: Infrastructure development project
• GSECARS: Sector 13, Advanced Photon Source