Skip Nav Destination
Close Modal
Search Results for
nuclear spins
Update search
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
NARROW
Format
Topics
Book Series
Date
Availability
1-20 of 123 Search Results for
nuclear spins
Follow your search
Access your saved searches in your account
Would you like to receive an alert when new items match your search?
1
Sort by
Image
Published: 15 December 2019
Fig. 1 Schematic showing the nuclear spin energy levels as a function of spin quantum number, I , and externally applied magnetic field, B 0 . The central transition (+1/2 to −1/2, in red) is denoted, and satellite transitions (in blue) also are shown. The Larmor frequency (splitting), ω L
More
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006650
EISBN: 978-1-62708-213-6
... Abstract This article focuses on the application of solid-state nuclear magnetic resonance (NMR) spectroscopy in materials science, especially for inorganic and organic polymer solids. It begins with a discussion on the general principles of NMR, providing information on nuclear spin...
Abstract
This article focuses on the application of solid-state nuclear magnetic resonance (NMR) spectroscopy in materials science, especially for inorganic and organic polymer solids. It begins with a discussion on the general principles of NMR, providing information on nuclear spin descriptions and line narrowing and spectral resolution and describing the impact of magnetic field on nuclear spins and the factors determining resonance frequency. This is followed by a description of various systems and equipment necessary for NMR spectroscopy. A discussion on general sampling for solid-state NMR, sample-spinning requirements, and extraneous signals is then included. Various factors pertinent to accurate calibration of the NMR spectrum are also described. The article provides information on some of the parameters both beneficial and problematic for processing NMR data. It ends with a description of the applications of NMR in glass science and ceramics.
Image
Published: 01 January 1986
Fig. 9 Hyperfine structure patterns. Three equally coupled nuclei with nuclear spin I = 1 2 and coupling constant A p plus two equally coupled I = 1 nuclei with coupling constant. (a) A N ≪ A p . (b) A N ≫ A p . (c) A N = A p
More
Series: ASM Handbook Archive
Volume: 10
Publisher: ASM International
Published: 01 January 1986
DOI: 10.31399/asm.hb.v10.a0001752
EISBN: 978-1-62708-178-8
... dipole and electric quadrupole undoubtedly exist, their interaction energies are orders of magnitude smaller and can be neglected. Values for the nuclear spin I , gyromagnetic ratio γ, and quadrupole moment Q for various nuclei are given in Table 1 . Also given are the naturally occurring relative...
Abstract
Nuclear magnetic resonance (NMR) is a form of radio frequency spectroscopy based on interactions between nuclear magnetic dipole or electric quadrupole moments and an applied magnetic field or electric-field gradient. This article provides an overview of the fundamental principles of nuclear magnetic resonance with emphasis on nuclei properties, the basic equation of nuclear magnetic resonance, the classical theory of nuclear magnetization, line broadening, and measurement sensitivity. It describes the pulse-echo method for observing NMR. The article provides useful information on ferromagnetic nuclear resonance and nuclear quadrupole resonance, and illustrates the experimental arrangement of NMR with a block diagram. It also presents several application examples.
Series: ASM Handbook Archive
Volume: 10
Publisher: ASM International
Published: 01 January 1986
DOI: 10.31399/asm.hb.v10.a0001750
EISBN: 978-1-62708-178-8
... carried out using ESR spectrometers irradiate the unpaired spins with a microwave frequency (approximately 10 10 Hz) and a RF (approximately 10 7 Hz). Many of these are nuclear-polarization techniques; therefore, the nuclear spin levels become populated with a Boltzmann factor characteristic of electron...
Abstract
Electron spin resonance (ESR), or electron paramagnetic resonance (EPR), is an analytical technique that can extract a great deal of information from any material containing unpaired electrons. This article explains how ESR works and where it applies in materials characterization. It describes a typical ESR spectrometer and explains how to tune it to optimize critical electromagnetic interactions in the test sample. It also identifies compounds and elements most suited for ESR analysis and explains how to extract supplementary information from test samples based on the time it takes electrons to return to equilibrium from their resonant state. Two of the most common methods for measuring this relaxation time are presented as are several application examples.
Image
Published: 15 December 2019
Fig. 3 Photo of a standard magic-angle spinning (MAS) nuclear magnetic resonance (NMR) probe (Chemagnetics/Varian wide-bore design, 89 mm, or 3.5 in.). The sample rotor is inserted into the MAS housing through the opening near the top of the probe. Air attachments, for both drive and bearing
More
Image
Published: 15 December 2019
Fig. 4 Examples of two widely available standard magic-angle spinning nuclear magnetic resonance rotor (sample holder) sizes. The cylindrical sleeve typically is zirconia, although silicon nitride also is used in some applications. The endcap, spacer, and drive tip shown for the 3.2 mm (0.13
More
Image
Published: 15 December 2019
Fig. 5 A 9.5 mm (0.37 in.) magic-angle spinning nuclear magnetic resonance (MAS NMR) rotor (drive tip not fully inserted for clarity) along with a typical glass insert that can contain nonsolid samples and fit tightly into the zirconia rotor for standard MAS NMR experiments. A synthetic
More
Image
Published: 15 December 2019
Fig. 8 The 31 P magic-angle spinning nuclear magnetic resonance spectra of crystalline Sn 2 P 2 O 7 with (a) no apodization and (b) 200 Hz Gaussian line broadening. Only the isotropic peaks due to the two Q 1 polyhedra are shown.
More
Image
Published: 15 December 2019
Fig. 9 The 31 P magic-angle spinning nuclear magnetic resonance spectra of glassy 10Na 2 O·45CaO·45P 2 O 5 . (a) Spectrum showing only the isotropic peaks. (b) Full spectrum with all spinning sidebands (ssb). Gaussian fits to the isotropic peaks and associated spinning sidebands are shown
More
Image
Published: 15 December 2019
Fig. 10 Examples of (a) 11 B magic-angle spinning nuclear magnetic resonance (MAS NMR) spectrum (16.4 T) of a sodium borosilicate glass with composition of 33Na 2 O-53B 2 O 3 -14SiO 2 and (b) 27 Al MAS NMR spectrum (16.4 T) of a glass with composition of 20CaO-30Al 2 O 3 -50SiO 2
More
Image
Published: 15 December 2019
Fig. 11 The 29 Si magic-angle spinning nuclear magnetic resonance spectrum of a cordierite (aluminosilicate) ceramic. This ceramic contains two different tetrahedral sites, denoted T 1 and T 2 , each of which is occupied by silicate tetrahedra having different numbers of next-nearest
More
Image
Published: 15 December 2019
Fig. 13 Solid-state magic-angle spinning nuclear magnetic resonance (NMR) spectra of (a) 29 Si and (b) 27 Al in a β-spodumene glass-ceramic, before and after heat treatment. Spinning sidebands are marked as “ssb,” and dashed curves denote fitted peaks.
More
Image
Published: 15 December 2019
Fig. 14 The 13 C cross-polarization magic-angle spinning nuclear magnetic resonance spectrum of modified cellulose powder. Different peaks are labeled with their position in the cellulose backbone: the hydroxypropyl (HP) and methoxy (Me) modifications.
More
Image
Published: 15 December 2019
Fig. 15 The 13 C cross-polarization magic-angle spinning nuclear magnetic resonance spectrum of silica gel treated with γ-aminopropyl triethoxysilane. Two resonances from unreacted ethoxide functionality are identified, and the other three resonances are from the aminopropyl group
More
Image
Published: 01 January 1986
the time period t w ( a to b ). The RF field is turned off suddenly at b. The spins begin to spread out as the result of an assumed magnetic-field inhomogeneity. Some spins precess faster than the rotating frame; others precess slower. A decaying nuclear signal is seen during bb ′. The spins have
More
Image
Published: 15 December 2019
Fig. 6 The 31 P nuclear magnetic resonance (NMR) spectra of crystalline Sn 2 P 2 O 7 at 11.7 T (ω L = 202 MHz) using a 3.2 mm (0.13 in.) magic-angle spinning (MAS) NMR probe. The spectrum in (a) was obtained under static conditions (i.e., no sample spinning), while the other spectra were
More
Image
Published: 15 December 2019
Fig. 12 Additional examples of solid-state nuclear magnetic resonance studies of ceramics. (a) 27 Al magic-angle spinning nuclear magnetic resonance (MAS NMR) spectrum of γ-alumina, showing resolution of aluminum in tetrahedral and octahedral sites. (b) 1 H MAS NMR spectrum of H-ZSM-5
More
Book Chapter
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006646
EISBN: 978-1-62708-213-6
... 1 1 + α where I e is the spin of the excited nuclear state, I g is the spin of the ground state, and α is the internal conversion coefficient. When the excited- and ground-state energy levels are split by a hyperfine field, the cross section is divided proportionally among the various...
Abstract
The Mossbauer effect (ME) is a spectroscopic method for observing nuclear gamma-ray fluorescence using the recoil-free transitions of a nucleus embedded in a solid lattice. This article provides an overview of the fundamental principles of ME, covering recoil-free fraction, absorption, selection rules, gamma-ray polarization, isomer shift, quadrupole interaction, and magnetic interaction. Experimental arrangement for obtaining ME spectra is described and several examples of the applications of ME are presented. The article contains tables listing some properties of Mossbauer transitions and principal methods used for producing ME sources.
Series: ASM Handbook Archive
Volume: 10
Publisher: ASM International
Published: 01 January 1986
DOI: 10.31399/asm.hb.v10.a0001753
EISBN: 978-1-62708-178-8
... 59.537 (radioactive) 68.3 5 2 5 2 32.55 0.06727 93.2 75 Note: E γ , is the γ-ray energy of the Mössbauer transition, t 1/2 is the half-life of the excited Mössbauer level, I e and I g are the spins of the excited- and ground-state nuclear levels, σ 0...
Abstract
The Mossbauer effect (ME) is a spectroscopic method for observing nuclear gamma-ray fluorescence based on recoil-free transitions in a nucleus embedded in a solid lattice. This article provides an overview of the fundamental principles of ME and related concepts such as recoil-free fraction, absorption cross section, gamma-ray polarization, isomer shift, and quadrupole and magnetic interactions. It illustrates the experimental arrangement for obtaining ME spectra and presents several application examples.
1