lecture 14: nmr spectroscopy of glass practice and...
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Lecture 14: NMR Spectroscopy of Glass – Practice and
Application : Quadrupolar Nuclei
Examine alkali borate glasses and the formation of tetrahedral borons
Examine alkali thioborate glasses and the formation of tetrahedral borons
Examine temperature dependence of spin lattice relaxation rate to probe ion dynamics in glass
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 2
I = 3/2 11B, 27Al….
Bray JNCS 73(1985)19-45
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 3
Powder pattern, amorphous, lineshape for I = 3/2
Bray JNCS 73(1985)19-45
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 4
11B NMR lineshapes for v=B2O3
Bray JNCS 73(1985)19-45
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 5
Theoretical line shapes for I = 3/2 spin
Bray JNCS 73(1985)19-45
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 6
NMR “wide line” CW spectra of v-B2O3
Bray JNCS 73(1985)19-45
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 7
Computer simulation of 11B NMR CW static spectra
Bray JNCS 73(1985)19-45
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 8
Comparison of derivative and integrated spectra
Bray JNCS 73(1985)19-45
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 9
Fraction of tetrahedral borons in alkali borate glasses
Bray JNCS 73(1985)19-45
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 10
Structural groups in alkali borate glasses
Feller, Dell, and Bray JNCS 51(1982)21-30
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 11
B2O3 glass
B2O3 glass exhibits high level
of IRO
Triangles form 6 membered
“boroxyl” rings
25% of borons are not in rings
BO3/2 “loose” triangles
75% of borons are in rings
B3(O)3(O3/2)
Equal numbers of boroxyl rings
and loose triangles
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 12
Tetrahedral boron formation in alkali borate glasses
M+BO4/2-1 units form with the
addition of M2O to BO3/2
Two tetrahedral units form, for every M2O added
xM2O + (1-x)B2O3 >>
f (BO4/2) N4 = [BO4]/Total B
= 2x/2(1-x)
= x/(1-x)
B fills it’s shell with octet of electrons
Alkali ion acts as a “spectator”ion not actively involved in bonding
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 13
Alkali modified borate glasses
M2O + B2O3 glasses
BO3/2 has 6 valence electrons
Three B-O single bonds
B can lower it’s energy by forming four B-O single bonds to over to 8 (full “octet”) valence electrons
It can do so by using M2O (M22+O=)
an electron donor
xM2O + (1-x)B2O3 >>
f (BO4/2) N4 = [BO4]/Total B
= 2x/2(1-x)
= x/(1-x)
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 14
Tetrahedral boron formation in alkali borate glasses
Two tetrahedral borons form for every M+ added
Alkali ions are “spectator” ions in the reaction
All of the alkali ions, Li, Na, K, Cs, and Rb act in the same manner
Affect is for M2O to cross-link borate glass structure
xM2O + (1-x)B2O3 >>
f (BO4/2) N4 = [BO4]/Total B
= 2x/2(1-x)
= x/(1-x)
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 15
Structure and NMR characteristics of various borate groups
Feller, Dell, and Bray JNCS 51(1982)21-30
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 16
Composition dependence of structural groups in Li2O + B2O3 glasses
Feller, Dell, and Bray JNCS 51(1982)21-30
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 17
B MASS NMR of alkali borate glasses
Prabakar, Rao, and Rao, Proc. R. Soc. Lond. A 429(1990)1-15
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 18
High field high spin rate B MASS NMR
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 19
Fraction of B4 in alkali borate glasses
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 20
B4 in alkali borosilicate glasses
Bray JNCS 73(1985)19-45
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 21
B3 in alkali borate glasses
Bray JNCS 73(1985)19-45
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 22
2D MASS NMR of 11B in B2O3
Zwanziger, Youngman JNCS 168(1994)293-297
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 23
2D 11B MASS NMR
Zwanziger, Youngman JNCS 168(1994)293-297
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 24
2D 11B MASS NMR
Zwanziger, Youngman JNCS 168(1994)293-297
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 25
Boroxyl ring fraction ~ 75%
Zwanziger, Youngman JNCS 168(1994)293-297
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 26
11B in alkali thioborate glasses
Sills and Martin, JNCS, 168(1994)86-96
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 27
v-B2O3 compared to v-B2S3
Sills and Martin, JNCS, 168(1994)86-96
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 28
Na2S + B2S3 glasses
Sills and Martin, JNCS, 168(1994)86-96
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 29
B4 in alkali thioborate glasses
Sills and Martin, JNCS, 168(1994)86-96
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 30
N4 in alkali thiobrate glasses
Sills and Martin, JNCS, 168(1994)86-96
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 31
C-Na2B4S7
Sills and Martin, JNCS, 168(1994)86-96
N4 = 1, no quadrupole
broadened line
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 32
xCs2S + (1-x)B2S311B NMR
Cho, Meyer, Martin JNCS 270(2000)205-214
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 33
N4 in x(Rb, Cs)2S + (1-x)B2S3 Glasses
Cho, Meyer, Martin JNCS 270(2000)205-214
Rb2S + B2S3Cs2S + B2S3
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 34
N4 in xM2S + (1-x)B2S3 Glasses
Cho, Meyer, Martin JNCS 270(2000)205-214
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 35
N4 in alkali thioborate glasses
Cho, Meyer, Martin JNCS 270(2000)205-214
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 36
Dithioborate group: Cs2B4S7
Cho, Meyer, Martin JNCS 270(2000)205-214
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 37
Formation of “normal” B4 in Cs2S + B2S3 glasses
Cho, Meyer, Martin JNCS 270(2000)205-214
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 38
Dithioborate structure with N4 = 1
Sills and Martin, JNCS, 168(1994)86-96
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 39
Na6B10S18 Crystal structure with N4 = 1
Royle, Cho, Martin JNCS 279(2001)97-109
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 40
Spin-Lattice relaxation time measurements
When the spins are flipped, it takes time for the spins to relax
to the lower (ground) energy state
This time is characterized by the spin-lattice relaxation time,
T1
T1 is typically very long for solids
Few mechanisms to enable the spin to release its spin
energy
T1 is typically very short for liquids
Rapid atomic, ionic, and/or molecular motion helps release
spin energy through diffusion
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 41
Spin-Lattice relaxation time measurements
Spin lattice relaxation T1 can be used therefore to examine
diffusion processes
Temperature dependence of T1 can be used as a measure
of molecular or atomic diffusion
Temperature dependence of T1 can also be used as a
measure of ionic diffusion
Temperature dependence of T1 is a measure of atomic level
displacements, diffusion
T1 can be compared to ionic conduction processes in glasses
Nuclear Spin Lattice Relaxation Time, T1
Nuclear Spin Lattice Relaxation Time, 1/T1 R1
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 42
Determination of the DAEs in Glass
Direct measurement through NMR
NSLR data
Conduction process is by the
percolation through low barrier
sites
Conductivity will only measure the
low energy barriers
NSLR measures all cations, both
contribute to NSLR T1 Glassy FIC
Crystalline FIC
Stevels & Taylor DAEs model,
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 43
NSLR to DAE to Conductivity
1 2 3 4 5 610
-1
100
101
102
103
104
z = 0.0; x = 0.55
Rela
xation R
ate
(s
-1)
1000 K/T
T1
4 MHz
8 MHz
0 20 40 60 80 100
Pro
ba
bil
ity
Activation Energy (kJ/mol)
x=0.35
x=0.45
x=0.55
1 2 3 4 5 6 710
-8
10-7
10-6
10-5
10-4
10-3
10-2
10-1
100
D.C
. C
on
du
ctivity (
Oh
m c
m)-1
1000 / Temp (K-1)
z=0.0;x=0.45
z=0.0;x=0.55
z=0.1;x=0.55
z=0.2;x=0.55
z=0.3;x=0.55
NSLR DAE Conductivity
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 44
NMR Relaxation of Spin Energy
H0
H1
z
xy
= H0
Rf pulse
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 45
Fluctuations from Ionic Motion
Distance
d/)m2/E(r5.0
act0
)Tk/Eexp(rTrBact0
Thermally activated cation
Not thermally activated
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 46
Bloombergen-Purcell-Pound (BPP) Theory
2
c
2
L
c
2
c
2
L
c
1
1
1
T41
T4
T1
TC
TT
1TR
Single relaxation time
theory
R1 = relaxation rate
T1 = relaxation time
L = Larmor frequency
C1 = coupling constant
c = correlation time
Tr
1T
c
Rela
xation R
ate
(s-1
)
1/T (K-1)
1TcL
NSLR Curve
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 47
Low Temperature Asymmetry
K. H. Kim, Solid State Ionics 91 (1996).
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 48
Distribution of Activation Energies
2
b
2
am
2
b
aNMR
E2
)EE(exp
E2
1)E(Z
J. Zarzycki, Glasses and the Vitreous State (1991).
0 20 40 60 80 100
Pro
babili
ty
Activation Energy, Ea (kJ/Mol)
Em
Em = average
Eb=standard deviation
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 49
NMR NSLR Data
Determination of the DAEs from NSLR T1 measurements
NMRNMR
aL
a
aL
a
LLdEZCTRTT
22
0
2211
414
1),(),(/1
22
1
1
2
2
2)(
1
2exp
2
1)1()(
amb
am
b
aNMR
EEE
Ey
E
EE
E
yEZ
Gaussian DAEs with Lorentzian “tail”, y ~ 0.2, to account for
low temperature, high frequency “extra” relaxation
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 50
DAEs from FIC Li2S + GeS2 Glasses
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 51
DAEs from FIC Li2S + GeS2 Glasses
Average of distribution shifts to
smaller activation energies
with increasing Li2S
Distribution does not change
shape significantly, all have ~
same FWHM
0.55 Glass is slightly
narrower
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 52
Multiple FIC Dynamics in Glass
“Multiple Channel” ion relaxation in
FIC glasses
R1 data show evidence of multiple
relaxation processes
Fast process at low T, slower
process at higher T
Alkali thioborate glasses are
speciated into tetrahedral borons
and trigonal borons with NBS
Are “slow” Li+ ions associated with
NBS?
Are “faster” Li+ ions associate with
BS4/2- groups?
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 53
Multiple FIC Dynamics in Glass
Relaxation spectra of both mobile
Li+ ions and immobile frame work
B ions were measured
Multiple-channel relaxation was
observed for Li+ ions
BS3 and BS4 units have different
relaxation rates and hence
difference DAEs to characterize
their dynamics
N4 of 0.7Li2S is 0.05
Most Li+ ions are associated with
BS33- groups, as evidenced in the
DAEs
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 54
DAE Fittings Two Distributions
0 20 40 60 80
ZN
MR (
Ea)
Activation Barrier Height, Ea (kJ/mol)
Ge sites
B sites
Total Distribution
1 2 3 4 5 60.1
1
10
100
1000
10000
z = 0.0; x = 0.55
Rela
xation R
ate
(s-1
)
1/T (K-1)
T1
70 kHz
4 MHz
8 MHz
xLi2S + (1-x)[0.5B2S3 + 0.5GeS4]
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 55
Effects of Li2S Addition
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.01
10
100
1000
Frequency = 8 MHz
xLi2S + (1-x)(0.5 B
2S
3 + 0.5 GeS
2)
Rela
xati
on
Rate
(s
-1)
1000/T (K-1)
x=0.35
x=0.45
x=0.55
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 56
Average Activation Energy
0.3 0.4 0.5 0.6 0.725
30
35
40
45
50
55
60
Ave
rag
e A
ctiva
tio
n E
ne
rgy,
Em (
kJ/m
ol)
mole fraction of Li2S
Boron site in xLi2S + (1-x)B
2S
3
Germanium site in xLi2S + (1-x)GeS
2
Germanium site in Ternary system
Boron site in Ternary system
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 57
LiI doped – Activation Energy
0.00 0.05 0.10 0.15 0.20 0.25 0.3020
25
30
35
40
45
50
55
60
Avera
ge A
ctivation E
nerg
y,
Em (
K)
mole fraction of LiI
Germanium site
Boron Site
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 58
1 2 3 4 5 60.1
1
10
100
1000
10000
z = 0.3 ; x = 0.55
Re
laxa
tio
n R
ate
(s-1
)
1/T (K-1)
4 MHz
8 MHz
1 2 3 4 5 60.1
1
10
100
1000
10000
z = 0.2 ; x = 0.55
Re
laxa
tio
n R
ate
(s-1
)
1/T (K-1)
T1
4 MHz
8 MHz
1 2 3 4 5 60.1
1
10
100
1000
10000
z = 0.1 ; x = 0.55
Re
laxa
tio
n R
ate
(s-1
)
1/T (K-1)
4 MHz
8 MHz
1 2 3 4 5 60.1
1
10
100
1000
10000
z = 0.0 ; x = 0.55
R
ela
xa
tio
n R
ate
(s
-1)
1/T (K-1)
T1
70 kHz
4 MHz
8 MHz
LiI Addition
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 59
Distribution of Activation Energies
xLi2S + (1-x)(0.5 B2S3 + 0.5 GeS2)
0 20 40 60 80 100
ZN
MR(
Ea)
Activation Energy (kJ/mol)
x=0.35
x=0.45
x=0.55
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 60
Distribution of Lithium atoms
Using coupling constants within 10% of
binary values yielded approximate Lithium
sharing fractions of:
Sample Germanium sites Boron sites
x=0.35 0.70 0.30
x=0.45 0.75 0.25
x=0.55 0.80 0.20
SWMartin ISU Lecture 14: NMR Spectroscopy of Glass: Quadrupole Nuclei in Glass 61
DAEs Treatment
Using a DAEs to treat ion conduction in glass is not new
Von Schweidler used a DRTs as early as 1907
Ann. Physik. 24(1907)711.
Cole and Cole, Cole and Davidson reported log Guassian DAEs
J. Chem. Phys. 9(1941) 341
H. E. Taylor used a DAEs to describe the dielectric relaxation
Modeling ’ and ” in soda-lime-silicate glass in 1955
Trans. Fara. Soc. 51(1955)873.
C. T. Moynihan used a log Guassian treatment
Modeling conductivity relaxation in CKN melts and glasses in 1972
Phys. Chem. Glasses 13(1972)171
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