Order

1
Order Disorder in Amorphous Oxides at
High-Pressure 2-Dimensional Multiple Quantum
MAS NMR Quantum Chemical Calculations
The 2nd Annual COMPRESS Meeting

• Sung Keun Lee, Yingwei Fei,
• George Cody Bjorn Mysen
• Geophysical Laboratory
• Carnegie Institution of Washington,
• Washington DC, 20015
• June 18 2003

2
Quantification of the Extent of Disorder in
Disordered Earth Materials
Silicate Melts Glasses Essential component
of igneous process Transport agents in the
chemical and physical differentiation of the
Earth. Fundamental Questions 1 Atomic
structures of silicate melts (T, P, X). 2
Microscopic origin of macroscopic properties. 3
Melting and dynamics of Mantle Melt-fluid
Interaction Mineralsmelts phase equilibria
affected by transport and thermodynamic
properties of melts.
(Lee SK in preparation)
3
METHODS I
Quantum Chemical Calculations
Statistical Mechanical Modeling Structure-Propert
y Relationship

• Density Functional Theory with Local Density
  approximation
• Hartree-Fock Methods

• Construction of Configuration Phase Space
  (coordinates and interactions)
• Establishment of Partition Functions(Q) e.g. A
  -kTlnQ(N,V.T)

Atomic configurations Energetics
distribution
Reactivity Vibration DOS NMR Chemical
Shielding
Probability (population) of clusters Order-
Disorder Parameters
Thermodynamic properties e.g. Activity
coefficient of silica Ionic diffusivity
4
METHODS II
NMR, X-ray Absorption, Optical Spectroscopy and
etc.

• 1 Resonance frequency in
• two-level system Short-range
• 2 Quantum coherence
• Peegtlte probability for excited states
• Pqegtltg Coherence
• 3 NMR relatively long
• decoherence time life time
• of excited state
• 4 Manipulation of spin
• system by multiple radio
• frequency pulses

Other Applications 1 Magnetic Res.
Imaging 2Nuclear magnetic
logging Porosity in the bore holes 3 Solution
NMR Protein Structure 4 NMR Quantum Computer
Enhancement of sensitivity and resolutions in
modern NMR techniques
5
OBJECTIVES
Toward Microscopic Origins of Geochemical
Processes Magma Melting Dynamics
Microscopic Origin of Thermodynamic Kinetic
Properties Viscosity Transport of
melts Activity coefficient of oxides Generation
of melt Site specific reactivity at the
fluid-solid interfaces
Statistical Mechanical Modeling
Quantification of the Extent of Disorder in
Silicates

• Theory
• Quantum Chemical Calculations

• Experiment
• Spectroscopy Scattering

6
Source of Non-randomness in Silicate Melts

• 1 Chemical Disorder
• a)_ Framework Disorder
• Al avoidance in aluminosilicates?
• Phase separation in silicate glasses?
• b)_ Non-Framework Disorder
• Distribution of non-framework cations NBO
• 2 Topological Short Range Order (TSRO)
• Bond angle length distribution function,

NBO/T
7
Framework Disorder in Silicates
(Lee and Stebbins, Am. Min 1999 Lee and
Stebbins Geochim. Cosmochim. Acta 2002)

• Degree of Al avoidance in aluminosilicates (Q)
• Degree of inter-dispersion in borosilicates (P)
• 2W the energy of the reaction
• T1-O-T1 T2-O-T2 2T1-O-T2

R(Si/T)1 where T Al or B
8
Oxygen-17 Solid State NMR

• Oxygen-17 spin 5/2, quadrupolar nuclei (e.g.
  Na, Al, B etc)
• Line broadening in quadrupolar nuclei

9
Oxygen-17 Solid State NMR

• Oxygen-17 spin 5/2, quadrupolar nuclei (e.g.
  Na, Al, B etc)
• Line broadening in quadrupolar nuclei

• Magic Angle Spinning (MAS) NMR

10
Oxygen-17 Solid State NMR

• Oxygen-17 spin 5/2, quadrupolar nuclei (e.g.
  Na, Al, B etc)
• Line broadening in quadrupolar nuclei

• Magic Angle Spinning (MAS) NMR

(Lee, Stebbins, Weiss, Kirkpatrick 2003,
Chemistry of Materials)
11
High Resolution Solid State NMRMQMAS
17O MAS
12
High Resolution Solid State NMRMQMAS
17O MAS
17O 3QMAS

• 17O MAS v.s.
• MQ (multiple quantum)
• MAS NMR spectra for
• Nepheline composition
• glass (NaAlSiO4).

(Frydman and Harwood JACS 1995 Kentgens and
Verhagen. Chem. Phys.Lett.1999 and etc)
(Lee and Stebbins, J. Non-Crystalline Solids
2000)
13
1-dimensional 17O MAS NMR
17O 3QMAS NMR Isotropic Projection
2-dimensional 17O 3QMAS NMR

• Nepheline composition glass (NaAlSiO4)

(Lee and Stebbins, J. Non-Crystalline Solids 2000)
14
MODEL SYSTEM Quantification of the Degree of Al
avoidance
Albite
17O MQMAS NMR spectra for sodium aluminosilicate
glasses (Na2O-Al2O3-2R.SiO2 ) with varying
R(Si/Al)

• 4Si-O-4Si increases with R(Si/Al).
• About 10 of 4Al-O-4Al and 4Si-O-4Si in
  Nepheline (R1) glass, demonstrating deviation
  from Al-avoidance rule.

Nepheline
(Lee and Stebbins, J. Phys. Chem. B 2000)
17O MAS NMR spectra
15
17O MQMAS NMR spectra for binary borosilicate
glasses with varying R(Si/B)
MODEL SYSTEM II Quantification of the Degree
of Phase Separation

• Binary borosilicate glasses B2O3-.SiO2
• The degree of mixing between the silicate network
  (4Si) and that comprised of three-coordinated
  boron (3B)
• Characteristics of 'pseudo-phase' spatial
  inhomogeniety
• Positive enthalpy of mixing from solution
  calorimetry, favoring clustering of 4Si and
  3B

16
MODEL SYSTEM II Quantification of the Degree of
Phase Separation
(P 0.62), P0 random P1 phase separation
17O MQMAS NMR spectra for binary borosilicate
glasses
(Lee and Stebbins, Geochim. Cosmochim Acta 2002
Lee et al. J. Phys. Chem. B 2001)
17
GENERAL FRAMEWORK
Al-avoidance
Clustering

• Oxygen site populations in silicate glasses
  including aluminosilicate and borosilicate
  glasses as a function of XT' which is the
  normalized mole fraction of framework cation (eg.
  T Al or B)

(Lee and Stebbins, Geochim. Cosmochim Acta 2002
Lee SK et al. J. Physical Chemistry B 2001)
18
Configurational Enthalpy I

• BS, Ca-AS and Na-AS the charge balanced binary
  borosilicate glasses (BO1.5-SiO2)
  Ca-aluminosilicate and Na-aluminosilicate
  glasses, respectively.
• Discrepancy in high Boron region

Blue solid line closed square
Calorimetry (Navrotsky et al. 1982 Hervig and
Navrotsky 1985)
Black solid line modelingNMR
(Lee and Stebbins, Geochim. Cosmochim. Acta 2002)
19
11B MQMAS NMR spectra for binary borosilicate
glasses
Formation of Boroxol Ring
(Lee and Stebbins, Geochim. Cosmochim. Acta 2002)
20
Microscopic Origins of Configurational Enthalpy
Activity Coefficient of Silica

• Quantum 1 molecular orbital calculations at the
  B3LYP/6-311G(d)//HF/3-21G level
• Quantum 2 at the B3LYP/6-311G(2d,p)//HF/3-21G
  level
• Closed circles calculated H config considering
  the formation of boroxol rings.

(Lee and Stebbins, Geochim. Cosmochim Acta 2002)
21
MODEL SYSTEM III
NBO in Ca-Na mixed cation silicate Glasses.
(CaO)x(Na2O)1-x3SiO2
1 Strong implications to the structure and
dynamics of silicate magmas 2 The fundamental
base glass for many technologically important
oxide glasses as well as window glasses since the
Roman empire.
1 Prevalence of Ca-Na pairs, and thus2
Considerable mixing of Ca and Na near NBO
17O MQMAS NMR spectra for Ca-Na mixed cation
silicate glasses at 9.4 T
(Lee and Stebbins,. J. Phys. Chem. B. 2003)
22
NBO in Ba-Mg Mixed Cation Silicate Glasses
17O MAS MQMAS NMR spectra for
(BaO)x(MgO)1-xSiO2 glasses at 7.1 T
23
1 Ba and Mg tend to show chemical order around
NBO forming only 3Ba-O-4Si and 1Ba2Mg-O-4Si
in BaMgSi2O6 glass 2 Ba also shows further
preferential proximity to both NBO and BO
compared with Mg.
(Lee,S.K. Mysen Cody, accepted, Phys. Rev. B.)
24
Extent of Disorder among Cations in Mixed Cation
Silicate Glasses
In N-M binary mixed cation silicate glasses, The
present results 1 highlight the tendency for
chemical ordering upon cation mixing in oxide
glasses. 2 provide an atomistic explanation
for diffusivity anomalies as well as
activity-composition relationship of silicate
melts.
(Lee,S.K. Mysen Cody, Phys. Rev. B. accepted)
25
TRANSPORT PROPERTIES Microscopic Origin of Mixed
Cation Effect

• Ion diffusivity in mixed cation silicate glasses
  and melts as a function of composition, disorder
  (Qm).

Negative deviation in cation diffusivity even in
random distribution of N-M, providing microscopic
origin of mixed cation effect
ENN total activation energy of the jump
processes from N to N
(Lee,S.K. Mysen Cody, accepted. Phys. Rev. B.)
26
The Extent of Disorder of Silicate Melts in
Earths Interior
MODEL SYSTEM V

• Na silicate (Na2Si3O7 ) glasses (NBO/T similar to
  tholeitic melts) and Na-aluminosilicate glasses
  quenched from melts at 6-10 GPa 1900 - 2070 K
  in a Multi-Anvil Apparatus
• CSRO (P) Site connectivity with P
• Possible heterogeneity in high pressure
• glass 4Si-O-5,6Si or 4Si-O-4Si
  and 6Si-O-6Si
• TRO (P) d(Na-O)(P), G(a, P)
• DNBO (P) NBO preference variation with P
• MRO (P) Variation of correlation length with
  pressure

27
Atomic Structure of Oxide Glasses at High Pressure

• Quantum chemical calculations of NMR chemical
  shielding
• B3LYP/6-311G(2d,p)//HF/6-311G(d)

Oxygen-17 Oxygen-17 isotropic chemical shift
difference between 4Si-O- 4Si 4Si-O-
5Si about 14 to 29 ppm Silicon-29
Silicon-27 chemical shift difference about 50
ppm between 4Si 5Si (Xue et al. Am. Min.
1991)
(Lee, SK, Fei, Y., Cody, G.D. Mysen, B.O,
Geophy. Res. Lett. in review)
28
Atomic Structure of Silicate Glasses at High
Pressure
17O 3QMAS NMR spectra for (Na2O)3SiO2 glasses at
7.1 T
(Lee, SK, Fei, Y., Cody, G.D. Mysen, B.O,
Geophy. Res. Lett. in review)
29
Comparison between MAS 3QMAS
(Lee, SK, Fei, Y., Cody, G.D. Mysen, B.O,
Geophy. Res. Lett. in review)
30
Aluminum Coordination with Pressure
Atomic Structure of Silicate Glasses Melts at
High Pressure Na-Aluminosilicates
27Al 3QMAS NMR spectra for (Na2O)0.75(Al2O3)0.253S
iO2 glasses at 7.1 T
31
Atomic Structure of Silicate Glasses Melts at
High Pressure Na-Aluminosilicates
17O 3QMAS NMR spectra for (Na2O)0.75(Al2O3)0.253Si
O2 glasses at 7.1 T
32
Distribution of 5Si and 6Si in the Silicate
Networks at High Pressure Melts

• Presence of Na-O-5.6Si formation of highly
  coordinated Si can occur at initially
  depolymerized silicon tetrahedra, Q3 and Q2.
• Chemical ordering among framework units favoring
  dissimilar pairs. (e.g. 4Si-O-5Si),
  suggesting low possibility of density fluctuation
  in the melts
• Activity coefficient of silica in the sodium
  silicate melts at high pressure is negatively
  deviated from the ideal solution model.

(Lee, SK, Fei, Y., Cody, G.D. Mysen, B.O,
Geophy. Res. Lett. in review)
33
Summary on Atomic Structures of Glass Melts

• Quantification of order in silicate glasses As
  functions of composition, temperature and
  pressure.
• Microscopic origin of melt properties
• Non randomness in atomic distributions in glasses
  and melts both positively (increase) and
  negatively (decrease) affect the activity
  coefficients of oxides in melts as well as other
  thermodynamic properties diffusivity (and thus
  viscosity) of melts.

34
CONCLUSIONS
Toward Atomic Scale Constraints of Geochemical
Processes
Microscopic Origin of Thermodynamic Kinetic
Properties as Functions of Various Aspects of
Disorder
Statistical Mechanical Modeling
Quantification of the Extent of Disorder in
Silicates Deviation from Randomness.

• Theory
• Quantum Chemical Calculations

• Experiment
• Spectroscopy Scattering

35
Acknowledgement

• NMR at 1atm Prof. J.F. Stebbins (Ph.D. advisor,
  Stanford). Drs. P. Zhao, Z. Xu S.Wang, J.V.
  Oglesby
• NMR, Raman, High-pressure facilities Geophysical
  Laboratory
• Drs. B. Mysen, G. Cody, Y. Fei., R. Hemley H.
  Mao
• E. Gregorianz, J. Lin, G. Mibe
• Quantum chemical calculations
• Prof. C. Musgrave, Drs. J.K. Kang, Y. Widjaja
  (Chem. Eng. Stanford). Prof. K.J. Cho (Mech. Eng.
  Stanford)
• Synthetic clay minerals samples
• Prof. R.J. Kirkpatrick Dr. C. Weiss
  (Geological Sci. Univ. Illinois, Urbana
  Champaign)
• Funding
• Stanford Graduate Fellowship,
• Carnegie Post Doctoral Fellowship (Carnegie
  Institution of Washington)
• NSF

36
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37
High Resolution Solid State NMR
Structure 1)_Structural Characterization of
organic molecules, protein and nuclei acids.
(2002 Nobel Prize winner, Chemistry KURT
WÜTHRICH ) Solution state NMR 2)_Structural
characterization of Solids Solid State NMR
3)_MRI, NML   RICHARD R. ERNST (1991 Nobel
Laureate in Chemistry for his contributions to
the development of the methodology of high
resolution nuclear magnetic resonance (NMR)
spectroscopy. ) Phase cycle and selection of
coherence   Dynamics 1)_measurement of many
aspects of correlation time. Relaxation
dynamics 2)_Chemical exchange, Diffusion and
etc   ETC 1)_NMR quantum computer (Solution or
Solids) 2)_Measurement of Porosity of Cookies etc
38
High Resolution Solid State NMR II
Spin Interactions in Nuclear Magnetic
Resonance     where external Hamiltonian,
reflecting the coupling of nuclear magnetic
dipole moment with external static and RF
magnetic field     , . g, and are the
gyromagnetic ratio, RF carrier frequency and
phase, respectively. The internal spin
interactions, HInt    
39
Influenced directly by anisotropic nuclear spin
interactions gt Dual aspect anisotropic spin
interaction a)_complicate the achievement of high
resolution spectra b)_can provide important
information about structure and dynamics.   Goal
of Solid State NMR manipulation of total spin
interaction to obtain a)_single desired
interactions while suppressing other undesired
terms or b)_correlation among the interactions
40
Dependence of 3QMAS Efficiency on Cq

• Spin-3/2 nuclei as a single crystal in the
  rotating frame on resonance. Considering only 1st
  order quadrupolar interactions,

Solid line numerical simulation Square
Experimental Na-23
(Lee and Stebbins Geochim. Cosmochim. Acta,
2003 Lee and Stebbins, J. Physical Chemistry B
2000 Vega and Noar J. Chem. Phys. 1981)
41
High Resolution Solid Sate NMR of quadrupolar
nuclei II. MAS NMR at high magnetic field

• Al-27 MAS NMR for Crystalline
• Aluminoborate.
• Quadrupolar interaction is inversely
• Proportional to the static magnetic
• fields

Gan et al., J. Am. Chem. Soc., (2002).
42
23Na MAS NMR spectra for sodium aluminosilicates
at varying magnetic fields
23Na MAS spectra of glasses on the NaAlO2-SiO2
join with varying Si/Al ratio (R) as labeled,
collected at 18.8T.
Na K-edge NEXAFS spectra for charge-balanced
sodium aluminosilicate glasses (NaAlSiRO2R2)
with varying R (Si/Al) as labeled.
23Na MAS spectra for NaAlSi2O6 glass at 9.4, 14.1
and 18.8 T, showing dramatic reduction in
quadrupolar broadening.
(Lee and Stebbins, Geochim. Cosmochim. Acta, 2003)
43
Atomic Structures of Covalent Oxide Glasses and
Melts
44
Kaolinite Pyrophyllite
(Lee, Stebbins, Weiss Kirkpatrick in press.
Chem. Mater.)
17O MAS and MQMAS NMR spectra for Layer
silicates at varying magnetic fields
(Lee and Stebbins, American Mineralogist 2003)
45
Length Scale of Interactions in Earth Materials
Science for Disordered Solids
Atomic and Nano Scale Nuclear Spin-Spin (Among
Electrons) Interactions
Macroscopic Properties Thermodynamic, Mechanical
, Electronic Properties Reactivity
Geological Process Generation and Transport of
Magma Distribution of Elements Weathering etc.
Chemistry Physics
Materials Science
Current Geological Sciences
Quantum Mechanics
Statistical Mechanics
Equilibrium Thermodynamics, Classical Mechanics
Kinetics
Field observation Geophysical Exploration
A Atomic Scale Information from Spectroscopy
Quantum Simulations Enhancement of
Sensitivity and Resolution M(A) Material
Properties Function of A. using Statistical
Mechanical Modeling GM(A) Implications for
Global Geochemical Processes
46
Degree of Al avoidance (Q) in aluminosilicate
Glasses
(Lee and Stebbins, J. Non-Crystalline Solids 2000)
47
MODEL SYSTEM III
NBO/T1
Peralkaline Na-Aluminosilicate Glasses Melts
with Varying NBO/T
NBO/T2
1 Absence of Na-O-4Al2 Increasing
Na-O-4Si with NBO/T
NBO/T0.4
NBO/T0
17O MAS MQMAS NMR spectra for sodium
aluminosilicate glasses_9.4T
(Lee, SK and Stebbins,J.F. in preparations)
48
Current Future Studies for Earth Materials
Science for Disordered Systems
Structural Dynamic Heterogeneity in Melts and
Glasses 1 Microscopic origin of Non-Debye
relaxation dynamics of silicate melts and
glasses? 2 Quantification of correlation
length, Dimensionality?
EXPERIMENT Multi-nuclear Solid State NMR
spectroscopy 1)_MQMAS, 2)_Double
Resonance 3)_High Field Synchrotron Inelastic
X-ray Scattering Absorption Spectroscopy
Vibrational Spectroscopy
THEORY SIMULATIONS Quantum Chemical
Calculations Molecular Dynamic
Simulations Statistical Mechanical Modeling
Microscopic Origin of Multi-component Melts
Properties and Geologic Processes 1
Development of statistical mechanical modeling of
the heterogeneous multi-components oxides (T, P,
X) Statistical Mechanical Modeling Mode-coupling
theory Energy landscape theory
Effect of Solid-solution and Alloying and their
effect on the Properties of Mantle and Core 1
Quantification of Disorder 2 Measurement of
Properties Quantification of Interactions in
Earth systems 1 Organic-Inorganic
Interfaces 2 Fluid-melts Fluid-mineral
Interactions.
49
Configurational Heat Capacity

• Na-aluminosilicate glasses at T1000K.
• Cp calc calculated configurational heat capacity
• Cp A-G obtained from calorimetry (Richet 1984)
  and viscosity measurement (Toplis et al. 1997)
  with Adam-Gibbs formalism (Adam and Gibbs 1964).

Nepheline
Jadeite
Albite
(Lee and Stebbins, American Mineralogist 1999)
50
TOPOLOGICAL DISORDER

• Bond angle and length distribution
• Significant fraction of macroscopic properties

Topological Entropy (Stsro) v.s. s (distribution)