NMR: hyperfine interactions in oxides and metals

Bastow, T. J.; Gibson, Mark; Forwood, C. T.

doi:10.1016/s0926-2040(98)00066-6

Cited by 38 publications

(33 citation statements)

References 16 publications

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“…The isotropic chemical shift and magnitude of the EFGparameters ( 49 C Q , g Q ) obtained for anatase are similar to the values obtained previously [4,8,6] except for d iso at À1038 ppm determined by Bastow et al [8] that is significantly different from the others. Regarding the CSA, the magnitude of d r in our study is 18 ppm larger than the one determined by Brãuniger et al [6] but agrees very well with the values obtained by single-crystal NMR [29].…”

Section: Resultssupporting

confidence: 88%

“…The EFG-parameters are almost identical to the ones determined by single-crystal NMR performed at 4.2 and 8.5 T [28] and the high field spectra even allowed for determination of a small d r of À30 ± 15 ppm which is in accordance with the value of À47 ± 20 ppm determined by a more recent single-crystal NMR study carried out at 11.7 T [29]. The isotropic chemical shift of À881 ppm is similar to the value of À860 ppm determined by single-crystal NMR [29] and less than 40 ppm off the values determined from a powder spectrum at 9.4 T [8]. Overall, a good fit was obtained at all fields, but particularly at 11.7 T the intensity of the 47 Ti lineshape is difficult to calculate accurately due to the experimental conditions previously mentioned.…”

Section: Resultssupporting

confidence: 86%

“…Single-pulse MAS or spin-echo MAS experiments have only proved successful for sites with a small/intermediate C Q such as in CdTiO 3 (perovskite) and anatase [4][5][6]. However, the static spin-echo approach is the more generally applicable method and by this method analysis of the three polymorphs of TiO 2 [7][8][9], a variety of ATiO 3 compounds, where A was a divalent cation, a range of ternary and quaternary titanates [5,10], Ti-USY samples [11], and Ba/Sr perovskites [12] have been conducted. Some of the second-order quadrupolar broadened lineshapes originating from the central transition have been more than 100 kHz wide at 14.1 T and in order to increase the S/N ratio Padro et al [10] used the static QCPMG experiment [13][14][15].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Separation of 47Ti and 49Ti solid-state NMR lineshapes by static QCPMG experiments at multiple fields

Larsen¹,

Farnan

Lipton

2006

Journal of Magnetic Resonance

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Section: Resultssupporting

confidence: 88%

Section: Resultssupporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Separation of 47Ti and 49Ti solid-state NMR lineshapes by static QCPMG experiments at multiple fields

Larsen¹,

Farnan

Lipton

2006

Journal of Magnetic Resonance

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“…All spectra were referenced against the secondary standard of SrTiO 3 ; where the titanium ions occupy sites of cubic symmetry and hence produce sharp, easily observable lines. Following the practice of recent solid-state NMR studies [4,10,11], the 49 Ti resonance of SrTiO 3 was set to 0 ppm. This secondary reference is shifted by À843 ppm against 49 Ti in liquid TiCl 4 ; the conventional shift standard for titanium [3].…”

Section: Methodsmentioning

confidence: 99%

“…A quadrupolar nucleus of special technological and scientifical interest is titanium, as it occurs in ferroelectric, piezoelectric and pyroelectric materials [1]. Accordingly, solid-state titanium NMR has been employed for examining technologically important compounds such as titania, TiO 2 [3][4][5], barium titanate, BaTiO 3 [3,4,[6][7][8], metal alloys [4] and zeolites [9]. Investigations of a range of ATiO 3 and A 2 TiO 4 compounds by Dupree and co-workers [10,11] have showed that a correlation between NMR interaction parameters of titanium nuclei and local structure exists.…”

Section: Introductionmentioning

confidence: 99%

Application of fast amplitude-modulated pulse trains for signal enhancement in static and magic-angle-spinning -NMR spectra

Bräuniger

Madhu

Pampel

et al. 2004

Solid State Nuclear Magnetic Resonance

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Nuclear Magnetic Resonance of Geological Materials and Glasses

Moran

Howe

2000

Encyclopedia of Analytical Chemistry

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This article concerns the application of nuclear magnetic resonance (NMR) spectroscopic techniques to the analysis of geological materials and glasses. It includes inorganic minerals and glasses, but does not cover soils and clay minerals to any extent. The first part presents an overview of solid‐state NMR experiments applicable to inorganic solids. The range of nuclei accessible by NMR and the particular requirements for obtaining good spectra of more difficult nuclei, including quadrupolar nuclei, are discussed. The experimental conditions under which solid‐state NMR can provide quantitative analytical measurements are also considered. NMR spectroscopy provides element‐specific speciation and structural information including coordination environment and bond distances. It is particularly valuable for the analysis of amorphous and partially crystalline materials not amenable to structure determination by X‐ray diffraction. NMR can detect and quantify materials containing multiple phases and can be used for in situ monitoring of phase transitions. It provides qualitative and quantitative speciation information for framework nuclei in glasses and is also capable of characterizing the dynamic behavior of mobile ions and solvent through relaxation, diffusion and chemical exchange experiments. Thus it has become an important technique for the study of hydrous minerals and gels and for ion‐conducting glasses. The sensitivity of NMR varies considerably, depending on the nucleus observed, its abundance and its chemical environment. NMR sensitivities and detection limits cannot compete with elemental analytical techniques such as X‐ray fluorescence. In addition, quantitation in solids requires careful control of experimental parameters and careful calibration to avoid artifacts. However, the selectivity of NMR as an analytical technique is unsurpassed and the development of specialist pulse sequences to measure specific local interactions in solids makes it particularly well suited to the analysis of geological materials and glasses. NMR imaging enables structural information to be resolved in three dimensions, although resolution in solid‐state imaging is limited to tens of micrometers at best owing to the broader line widths and lower signal‐to‐noise ratios compared with liquids. However, capabilities in this field are being extended all the time and the application of NMR imaging techniques in materials analysis is expanding steadily. An alternative to conventional imaging is NMR force microscopy, which shows potential for surface mapping at higher resolutions. The applications section is organized on the basis of the materials being analyzed. Within each section, NMR techniques are classified according to the observed nuclei. The emphasis is on more recent applications and on developments leading to enhanced resolution and sensitivity. Silicates and aluminosilicates represent the largest class of applications, followed by phosphate, borate and other oxide glasses. Sol–gel materials and the reactions leading to gel formation are also discussed, as are hydrous materials more generally. The other important areas of application reviewed are minerals, ceramics, high‐temperature melts and ion‐conducting glasses. Finally, the applications of NMR imaging in this field, although sparse at present, are potentially very great. This is illustrated by two major areas of application to date, namely the imaging of bone minerals and cement and concrete.

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NMR: hyperfine interactions in oxides and metals

Cited by 38 publications

References 16 publications

Separation of 47Ti and 49Ti solid-state NMR lineshapes by static QCPMG experiments at multiple fields

Separation of 47Ti and 49Ti solid-state NMR lineshapes by static QCPMG experiments at multiple fields

Application of fast amplitude-modulated pulse trains for signal enhancement in static and magic-angle-spinning -NMR spectra

Nuclear Magnetic Resonance of Geological Materials and Glasses

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