Pressure Calibration in DAC -- Challenges for Increasing Accuracy and Precision Ho-kwang Mao Carnegie Institution of Washington Pressure Calibration Workshop January 26-28, 2007

GPa 10 MPa – 1 GPa GPa High temperatures Different Challenges in Different P-T Ranges 2

Topics Primary calibration (accuracy) Secondary calibration (precision) Hydrostaticity X-ray diffraction (axial and radial) Optical spectroscopy (Brillouin, Raman, fluorescence) Inelastic x-ray scattering spectroscopy 3

Goals Primary calibration (accuracy) GPa  P/P = ±1% GPa  P/P = ±1% High temperatures -- at 100 GPa-2500 K  P/P = ±1% Secondary calibration (precision) 10 MPa – 1 GPa  P = ±5 MPa GPa  P/P = ±0.2% GPa  P/P = ±0.2% 4

Goals Primary calibration (accuracy) GPa  P/P = ±1% GPa  P/P = ±1% High temperatures -- at 100 GPa-2500 K  P/P = ±1% Secondary calibration (precision) 10 MPa – 1 GPa  P = ±5 MPa GPa  P/P = ±0.2% GPa  P/P = ±0.2% 4

Primary calibration requires measurements of two independent functions related to pressure. Examples: F and A – free rotation piston-cylinder U S and U P – shock Hugoniot V  and  – DAC V  2 = K/  K =  dP/d  P =  V  2 d . 5

Primary calibration requires measurements of two independent functions related to pressure. Examples: F and A – free rotation piston-cylinder U S and U P – shock Hugoniot V  and  – DAC V  2 = K/  K =  dP/d  P =  V  2 d . 5

Goals Primary calibration (accuracy) GPa  P/P = ±1% GPa  P/P = ±1% High temperatures -- at 100 GPa-2500 K  P/P = ±1% Secondary calibration (precision) 10 MPa – 1 GPa  P = ±5 MPa GPa  P/P = ±0.2% GPa  P/P = ±0.2% 6

Pressure calibration,  P/P ±1%  from x-ray diffraction V   from Brillouin scattering P-  EOS by integration (Primary) Ruby fluorescence shift Calibrated by MgO P-  EOS (Secondary) Zha, Mao, Hemley, PNAS (2000) 6

Goals Primary calibration (accuracy) GPa  P/P = ±1% GPa  P/P = ±1% High temperatures -- at 100 GPa-2500 K  P/P = ±1% Secondary calibration (precision) 10 MPa – 1 GPa  P = ±5 MPa GPa  P/P = ±0.2% GPa  P/P = ±0.2% 10

Secondary Calibration of Six Metals XRD,  ±0.2%,  P/P ±1% Ruby fluorescence shift Calibrated by MgO P-  EOS (Secondary) Dewaele, Loubeyre, Mezouar, PRB (2004)

Goals Primary calibration (accuracy) GPa  P/P = ±1% GPa  P/P = ±1% High temperatures -- at 100 GPa-2500 K  P/P = ±1% Secondary calibration (precision) 10 MPa – 1 GPa  P = ±5 MPa GPa  P/P = ±0.2% GPa  P/P = ±0.2% 12

High T Primary Calibration Using V  and  Problem: K S = (1 +  T) K T Difference ~10% at 3000 K introduces >1% error A practical alternative is to combine 300 K primary calibration and high resolution high P-T XRD 13

Pressure (GPa) Volume (Å 3 ) 300 K 1400 K 2000 K Fs20 ppv Temperature (K) (V T – V 300 )/V Post-perovskite P-V-T W. Mao et al, submitted (2007)

Goals Primary calibration (accuracy) GPa  P/P = ±1% GPa  P/P = ±1% High temperatures -- at 100 GPa-2500 K  P/P = ±1% Secondary calibration (precision) 10 MPa – 1 GPa  P = ±5 MPa GPa  P/P = ±0.2% GPa  P/P = ±0.2% 15

- BIOCHEMICAL REACTIONS IN HYDROTHERMA FLUIDS - LIFE IN EXTREME ENVIRONMENTS (>1600 MPa) [Sharma et al., Science 295, 1514 (2002)] - PRESSURE EFFECTS ON STRUCTURE-FUNCTION RELATIONS Single-Crystal Diffraction of Cow Pea Mosaic Virus [Lin et al., Acta Crystal. D61, 737 (2005)] Biomaterials -- bacteria and virus MPa

Hydrogen storage in clathrate Energy, keV d-spacing, Å Intensity H 2 -2H 2 O S-II clathrate-- A clean and efficient material for hydrogen storage 0.2 GPa 10 kPa 77 K HH-sII 280 H 2 +H 2 O 17 W Mao et al, Science (2002)-- Synthesis S-II at HP and quenched to low PT; Lokshin et al, PRL (2004)-- Identification of H 2 in S-II cages with neutron; Florusse et al, Science (2004)-- Stabilized to 280K at 1 bar

Goals Primary calibration (accuracy) GPa  P/P = ±1% GPa  P/P = ±1% High temperatures -- at 100 GPa-2500 K  P/P = ±1% Secondary calibration (precision) 10 MPa – 1 GPa  P = ±5 MPa GPa  P/P = ±0.2% GPa  P/P = ±0.2% 18

High Pressure Experiments Challenge Existing Understanding of Seismic Waves in Deep Earth The crushing pressures in the lower mantle squeeze atoms and electrons so closely together that they interact differently from under normal conditions, even forcing spinning electrons to pair up in orbits. In theory, seismic-wave behavior at those depths may result from the vice-gripping pressure effect on the electron spin-state of iron in lower-mantle materials. Carnegie’s team performed ultra high-pressure experiments on the most abundant oxide material there, magnesiowüstite (Mg,Fe)O, and found that the changing electron spin states of iron in that mineral drastically affect the elastic properties of magnesiowüstite. The research may explain the complex seismic wave anomalies observed in the lowermost mantle. Normalized volume of magnesiowüstite, (Mg0.83,Fe0.17)O, as a function of pressure at 300 K. Jung-Fu Lin, Viktor V. Struzhkin, Steven D. Jacobsen, Michael Y. Hu, Paul Chow, Jennifer Kung, Haozhe Liu, Ho-kwang Mao and Russell J. Hemley; "Spin transition of iron in magnesiowüstite in the Earth's lower mantle" Nature 436, (21 July 2005) Spin transition of iron in magnesiowüstite 19

Goals Primary calibration (accuracy) GPa  P/P = ±1% GPa  P/P = ±1% High temperatures -- at 100 GPa-2500 K  P/P = ±1% Secondary calibration (precision) 10 MPa – 1 GPa  P = ±5 MPa GPa  P/P = ±0.2% GPa  P/P = ±0.2% 20

Topics Primary calibration (accuracy) Secondary calibration (precision) Hydrostaticity X-ray diffraction (axial and radial) Optical spectroscopy (Brillouin, Raman, fluorescence) Inelastic x-ray scattering spectroscopy 21

Shear strength of argon Mao, et al, J. Phys.: Cond. Mat. (2006) Primary calibration needs to use He medium

Topics Primary calibration (accuracy) Secondary calibration (precision) Hydrostaticity X-ray diffraction (axial and radial) Optical spectroscopy (Brillouin, Raman, fluorescence) Inelastic x-ray scattering spectroscopy 23

Attaining  V  /V  ± 1% Ultrasonic measurements Nuclear resonant inelastic x-ray scattering Brillouin Spectroscopy Inelastic x-ray scattering spectroscopy 24

Attaining  V  /V  ± 1% Ultrasonic measurements to GPa? Nuclear resonant inelastic x-ray scattering Brillouin Spectroscopy Inelastic x-ray scattering spectroscopy 25

Nuclear resonant inelastic x-ray spectroscopy (NRIXS)

Attaining  V  /V  ± 1% Ultrasonic measurements Nuclear resonant inelastic x-ray scattering Brillouin Spectroscopy Inelastic x-ray scattering spectroscopy 27

Brillouin Spectroscopy Single crystal V  accuracy ±1% Polycrystalline V  accuracy 3-10% 28

Fiquet et al., Science 2001 Antonangeli et al., EPSL 2004 Antonangeli et al, PRL 2005 Single-xtal Co at 39 GPa Inelastic x-ray scattering spectroscopy (IXSS) Poly-xtal hcp-Fe to over 100 GPa Determines phonon dispersion

Inelastic x-ray scattering spectroscopy (IXSS) Improve energy resolution from 6 meV to 1 meV to get to  V  /V  ± 1% 35XU, SPring-8 30 hcp-Fe at 52 GPa W. Mao et al, in prep.

High Res. XRD with panoramic DAC   ctn   Going from 2  = 10º to 2  = 90º,  /  improves 10x ! UNICAT, 34-ID, APS, ANL

Summary: Achievable Goals Primary calibration (accuracy) Hydrostaticity of He?  P/P = 0.2-1%? Single-xtl Brillouin scattering or single-xtl ixss to GPa  V  / V  = ±1% Polycrystalline XRD to GPa and 100 GPa-2500 K  /  = ±0.2%  P/P = ±1% Secondary calibration (precision) High resolution XRD at 10 MPa- 300 GPa  /  = ±0.02%  P/P = ±0.2% Optical calibration  P/P = ±0.2% 32