Spin relaxation and ultra-slow Li motion in an aluminosilicate glass ceramic

Böhmer, Roland; Qi, Fei

doi:10.1016/j.ssnmr.2006.11.002

Cited by 38 publications

(39 citation statements)

References 40 publications

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“…The relaxation time T 1Q of the spin-alignment state can be estimated from separate measurements of the spin-lattice relaxation time T 1 , which for slow motions, ω L τ 1, and in polycrystalline samples is related to T 1Q according to T 1 /T 1Q = 25/8. 41,42 Spin diffusion leads to magnetization transfer via a flip-flop process among the spins. This process is caused by dipolar interactions that are quite effective in the glasses studied here due to the large gyromagnetic ratio of the 7 Li nuclei and can lead to a substantial damping of the echo amplitude at long times and low temperatures when the ion dynamics become slow.…”

Section: B Stimulated Echoesmentioning

confidence: 99%

“…(8) and account for the decay of the spin-alignment state by an exponential function with a time constant (8/25) × T 1 and a T 1 determined by separate spin-lattice relaxation measurements. 41,42 For compositions with a finite boron concentration, i.e., for all samples except x = 0.0, spin-lattice relaxation is relatively slow so that no substantial damping of F 2 is expected.…”

Section: Dynamics Probed By Two-time Correlation Functionsmentioning

confidence: 99%

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NMR and conductivity studies of the mixed glass former effect in lithium borophosphate glasses

Storek

Böhmer

Martin

et al. 2012

The Journal of Chemical Physics

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Alkali ion charge transport has been studied in a series of mixed glass former lithium borophosphate glasses of composition 0.33Li 2 O + 0.67[xB 2 O 3 + (1 -x)P 2 O 5 ]. The entire concentration range, 0.0 ≤ x ≤ 1.0, from pure glassy Li 2 P 4 O 11 to pure glassy Li 2 B 4 O 7 has been examined while keeping the molar fraction of Li 2 O constant. Electrical conductivity measurements and nuclear magnetic resonance techniques such as spin relaxometry, line shape analysis, and stimulated-echo spectroscopy were used to examine the temperature and frequency dependence of the Li + ion motion over wide ranges of time scale and temperature. By accurately determining motional time scales and activation energies over the entire composition range the ion dynamics and the charge transport are found to be fastest if the borate and the phosphate fractions are similar. The nonlinear variation of the charge conduction, the most notable feature of the mixed glass former effect, is discussed in terms of the composition dependence of network former units which determine the local glass structure. Electrical conductivity measurements and nuclear magnetic resonance techniques such as spin relaxometry, line shape analysis, and stimulated-echo spectroscopy were used to examine the temperature and frequency dependence of the Li + ion motion over wide ranges of time scale and temperature. By accurately determining motional time scales and activation energies over the entire composition range the ion dynamics and the charge transport are found to be fastest if the borate and the phosphate fractions are similar. The nonlinear variation of the charge conduction, the most notable feature of the mixed glass former effect, is discussed in terms of the composition dependence of network former units which determine the local glass structure.

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Section: B Stimulated Echoesmentioning

confidence: 99%

Section: Dynamics Probed By Two-time Correlation Functionsmentioning

confidence: 99%

NMR and conductivity studies of the mixed glass former effect in lithium borophosphate glasses

Storek

Böhmer

Martin

et al. 2012

The Journal of Chemical Physics

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“…Advantageous over already well-established Li NMR methods [15][16][17][18][19] is the use of 7 Li stimulated echo, or more precisely, spin-alignment echo ͑SAE͒ NMR which has so far been applied mainly to crystalline Li conductors. 17,[20][21][22][23][24][25][26][27][28][29][30][31][32] Similar to modern twodimensional 6 Li and 7 Li exchange NMR spectroscopy, 33-38 7 Li SAE NMR is sensitive to extremely slow cation exchange processes and gives access to diffusion parameters from a microscopic point of view. Thus, it is possible to record single-particle motional correlation functions, 39 from which the atomic jump rate can be directly obtained, i.e., without the help of a diffusion model.…”

Section: Introductionmentioning

confidence: 99%

Atomic-scale measurement of ultraslow Li motions in glassyLiAlSi2O6by two-timeL6
Wilkening
¹
,
Kuhn
²
,
Heitjans
³

2008
Phys. Rev. B
59
4
50
0
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6 Li spin-alignment echo ͑SAE͒ nuclear-magnetic-resonance ͑NMR͒ spectroscopy is used to monitor singleparticle two-time correlation functions in LiAlSi 2 O 6 glass. The method, here applied in the temperature range from 300 to 400 K, is sensitive to ultraslow Li hopping processes with rates ͑1 / SAE ͒ down to 10 jumps/s. The use of a sample with natural 6 Li abundance allowed the measurement of pure NMR spin-alignment echoes which are damped with increasing mixing time exclusively by slow Li jumps, i.e., free of influences arising from, e.g., interfering spin-diffusion effects. The considerably stretched correlation functions reveal the presence of a broad distribution of jump rates. The results are comprehensively compared with those recently obtained from both 7 Li SAE and 7 Li spin-lattice relaxation NMR as well as from dc conductivity measurements. Interestingly, the activation energy of the latter, which are sensitive to long-range Li transport parameters, is in good agreement with that microscopically probed by 6 Li SAE NMR, here.

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“…Two-time stimulated echo NMR spectroscopy [59,60] exploits the heterogeneity of the micro-domain orientations within the clay sediment (see Figure 1). For 2 H nuclei, these heterogeneities of the clay platelets' orientation induce heterogeneities of the residual quadrupolar coupling felt by the confined water molecules (Equation (A6)).…”

Section: Two-time Stimulated Echo Attenuationmentioning

confidence: 99%

“…We have used multi-quanta spin-locking NMR relaxometry measurements to determine the average residence time of the water molecules and some neutralizing counterions within the interlamellar space between the clay platelets inside each micro-domain. Furthermore, two-time stimulated echo NMR spectroscopy [59] was used to quantify the time-scale required by the water molecules to probe micro-domains with different orientations [52,53,60].…”

Section: Introductionmentioning

confidence: 99%

Multi-Quanta Spin-Locking Nuclear Magnetic Resonance Relaxation Measurements: An Analysis of the Long-Time Dynamical Properties of Ions and Water Molecules Confined within Dense Clay Sediments

Porion

Delville

2017

Magnetochemistry

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Solid/liquid interfaces are exploited in various industrial applications because confinement strongly modifies the physico-chemical properties of bulk fluids. In that context, investigating the dynamical properties of confined fluids is crucial to identify and better understand the key factors responsible for their behavior and to optimize their structural and dynamical properties. For that purpose, we have developed multi-quanta spin-locking nuclear magnetic resonance relaxometry of quadrupolar nuclei in order to fill the gap between the time-scales accessible by classical procedures (like dielectric relaxation, inelastic and quasi-elastic neutron scattering) and obtain otherwise unattainable dynamical information. This work focuses on the use of quadrupolar nuclei (like 2 H, 7 Li and 133 Cs), because quadrupolar isotopes are the most abundant NMR probes in the periodic table. Clay sediments are the confining media selected for this study because they are ubiquitous materials implied in numerous industrial applications (ionic exchange, pollutant absorption, drilling, waste storing, cracking and heterogeneous catalysis).

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Spin relaxation and ultra-slow Li motion in an aluminosilicate glass ceramic

Cited by 38 publications

References 40 publications

NMR and conductivity studies of the mixed glass former effect in lithium borophosphate glasses

NMR and conductivity studies of the mixed glass former effect in lithium borophosphate glasses

Atomic-scale measurement of ultraslow Li motions in glassyLiAlSi2O6by two-timeL6
Wilkening
¹
,
Kuhn
²
,
Heitjans
³

2008
Phys. Rev. B
59
4
50
0
View full text Add to dashboard Cite

Multi-Quanta Spin-Locking Nuclear Magnetic Resonance Relaxation Measurements: An Analysis of the Long-Time Dynamical Properties of Ions and Water Molecules Confined within Dense Clay Sediments

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Spin relaxation and ultra-slow Li motion in an aluminosilicate glass ceramic

Cited by 38 publications

References 40 publications

NMR and conductivity studies of the mixed glass former effect in lithium borophosphate glasses

NMR and conductivity studies of the mixed glass former effect in lithium borophosphate glasses

Atomic-scale measurement of ultraslow Li motions in glassyLiAlSi2O6by two-timeL6Wilkening1, Kuhn2, Heitjans3 2008Phys. Rev. B594500View full textAdd to dashboardCite

Multi-Quanta Spin-Locking Nuclear Magnetic Resonance Relaxation Measurements: An Analysis of the Long-Time Dynamical Properties of Ions and Water Molecules Confined within Dense Clay Sediments

Contact Info

Product

Resources

About

Atomic-scale measurement of ultraslow Li motions in glassyLiAlSi2O6by two-timeL6
Wilkening
¹
,
Kuhn
²
,
Heitjans
³

2008
Phys. Rev. B
59
4
50
0
View full text Add to dashboard Cite