Theoretical and experimental study of quadrupolar echoes in solid state NMR

Dumazy, Y; Amoureux, Jean‐Paul; Fernandéz, Christian

doi:10.1080/00268979709482680

Cited by 11 publications

(21 citation statements)

References 27 publications

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“…The 29 Si spectra were obtained from single pulse experiments, with p/2 duration of 4.2 ls and recycle delays of 3600 s. 23 Na NMR spectra were measured with short single pulses of 0.5 ls (p/12) and recycle delay of 0.5 s. Also, spin-echo experiments were carried out using the sequence proposed by Dumazy et al [10] for spin I = 3/2, which minimizes spectral distortions arising from ill-refocused signals (transients and anti-echoes). Echoes were generated from two low power pulses (cB 1 = 10 KHz) of 2.6 ls and 5.2 ls separated by 30 ls delay and phasecycled according to Ref.…”

Section: Experimental Techniquesmentioning

confidence: 99%

Study of the structure of alkali–silica reaction gel by high-resolution NMR spectroscopy

Tambelli

Schneider

Hasparyk

et al. 2006

Journal of Non-Crystalline Solids

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Section: Experimental Techniquesmentioning

confidence: 99%

Study of the structure of alkali–silica reaction gel by high-resolution NMR spectroscopy

Tambelli

Schneider

Hasparyk

et al. 2006

Journal of Non-Crystalline Solids

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“…The HS technique [17] was combined with the HE [18] or QCPMG [16] experiment to examine MAS salts were carried out using SIMPSON [47] and WSOLIDS. [48] For SIMPSON simulations, the zcw class of crystal files, ranging in size from 4180 to 28 656, were used to calculate 53 Cr NMR spectra.…”

Section: Background Theorymentioning

confidence: 99%

“…Solid-state 53 Cr NMR spectra of stationary chromate and dichromate samples were acquired using the quadrupolar Carr-Purcell Meiboom-Gill (QCPMG) [16] experiment, which offers a significant gain in signal-to-noise over traditional techniques and decreases experiment times. In addition, the utility of hyperbolic secant (HS) pulses, [17] combined with the Hahnecho (HE) [18] or QCPMG [16] …”

mentioning

confidence: 99%

A solid‐state ⁵³Cr NMR study of chromate and dichromate salts

Forgeron¹,

Wasylishen²

2007

Magnetic Reson in Chemistry

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Solid-state (53)Cr NMR spectra of a series of chromate (CrO4(2-)) and dichromate (Cr2O7(2-)) salts have been examined by employing the stepped-frequency quadrupolar Carr-Purcell Meiboom-Gill (QCPMG) experiment and high applied magnetic field strengths, 11.75 and 18.8 T. Cr-53 nuclear quadrupolar coupling constants, CQ(53Cr), ranging from 1.23 to 5.01 MHz for the Cr(4(2-) salts and 7.25 to 8.14 MHz for the Cr2O7(2-) salts have been measured. For the dichromate salts, this corresponds to central transition 53Cr NMR lineshapes of 200-250 kHz at 18.8 T. The use of hyperbolic secant (HS) pulses in combination with the Hahn-echo (HE) or QCPMG experiment results in significant sensitivity enhancements when acquiring 53Cr NMR spectra of magic-angle spinning (MAS) samples, provided the MAS rate is fast with respect to the second-order quadrupolar interaction. For the CrO4(2-) and Cr2O7(2-) salts, the anisotropic chromium magnetic shielding interaction is generally negligible compared to the second-order 53Cr nuclear quadrupolar interaction. No simple correlation between the structure of the CrO4(2-) and Cr2O7(2-) anions and the observed CQ(53Cr) values has been found.

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“…The quadrupolar interactions lead to much more complex magnetization trajectories than in spin-1/2 systems, and so standard dipole-dephasing experiments become difficult to apply quantitatively. 15,16 In addition, the bonding environments of boron are more diverse than those of silicon, leading to a wider variety of sites and couplings.…”

Section: Introductionmentioning

confidence: 99%

Structural Similarity on Multiple Length Scales and Its Relation to Devitrification Mechanism: A Solid-State NMR Study of Alkali Diborate Glasses and Crystals

et al. 2009

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The nature of the devitrification process is a fundamental problem in glass science and governs the ultimate stability of glass. It is hypothesized that the devitrification mechanism of a given glass composition is strongly correlated with the extent of structural similarity at the intermediate-range level between the glass and crystal phase to which it transforms. However, relatively little information is available to test this hypothesis because of the lack of long-range periodicity in glass and the absence of effective analysis methods. In this work Li 2 O-2B 2 O 3 (L2B) and Na 2 O-2B 2 O 3 (N2B) glasses, which respectively exhibit homogeneous (internal) and heterogeneous (surface) devitrification mechanisms, and corresponding crystals were prepared and comprehensively studied by using multiple solid state NMR techniques. Of those, 11B MAS and MQMAS experiments were applied to reveal short-range order information; Na} rotational echo double resonance (REDOR) experiments were used to determine homonuclear and heteronuclear interactions that can reflect the intermediate-range order. It was found that the local bonding environments of the L2B crystal and glass are quite similar, whereas there are significant differences in the N2B system. Moreover, the experimental results indicated that the second moment (M 2 ) values of both homo-and heterodipolar interactions measured for the L2B glass are very close to those of its isochemical crystal, in contrast, the M 2 values for N2B glass differ significantly from those of its crystal phase. These observations indicate the existence of a strong correlation between structural similarity at both the short and intermediate length scale, and nucleation mechanism.

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Theoretical and experimental study of quadrupolar echoes in solid state NMR

Cited by 11 publications

References 27 publications

Study of the structure of alkali–silica reaction gel by high-resolution NMR spectroscopy

Study of the structure of alkali–silica reaction gel by high-resolution NMR spectroscopy

A solid‐state ⁵³Cr NMR study of chromate and dichromate salts

Structural Similarity on Multiple Length Scales and Its Relation to Devitrification Mechanism: A Solid-State NMR Study of Alkali Diborate Glasses and Crystals

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Theoretical and experimental study of quadrupolar echoes in solid state NMR

Cited by 11 publications

References 27 publications

Study of the structure of alkali–silica reaction gel by high-resolution NMR spectroscopy

Study of the structure of alkali–silica reaction gel by high-resolution NMR spectroscopy

A solid‐state 53Cr NMR study of chromate and dichromate salts

Structural Similarity on Multiple Length Scales and Its Relation to Devitrification Mechanism: A Solid-State NMR Study of Alkali Diborate Glasses and Crystals

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A solid‐state ⁵³Cr NMR study of chromate and dichromate salts