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The Fermi contact interaction is the magnetic interaction between an electron and an atomic nucleus. Its major manifestation is in electron paramagnetic resonance and nuclear magnetic resonance spectroscopies, where it is responsible for the appearance of isotropic hyperfine coupling. This requires that the electron occupy an s-orbital.
The electron Zeeman interaction describes the interaction between an electron spin and the applied magnetic field. The nuclear Zeeman interaction is the interaction of the magnetic moment of the proton with an applied magnetic field. The hyperfine interaction is the coupling between the electron spin and the proton's nuclear spin.
Nuclear quadrupole resonance spectroscopy or NQR is a chemical analysis technique related to nuclear magnetic resonance . Unlike NMR, NQR transitions of nuclei can be detected in the absence of a magnetic field , and for this reason NQR spectroscopy is referred to as " zero Field NMR ".
Bruker 700 MHz nuclear magnetic resonance (NMR) spectrometer. Nuclear Magnetic Resonance (NMR) basic principles. Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a strong constant magnetic field are disturbed by a weak oscillating magnetic field (in the near field [1]) and respond by producing an electromagnetic signal with a frequency characteristic of the magnetic ...
In physics and chemistry, specifically in nuclear magnetic resonance (NMR), magnetic resonance imaging (MRI), and electron spin resonance (ESR), the Bloch equations are a set of macroscopic equations that are used to calculate the nuclear magnetization M = (M x, M y, M z) as a function of time when relaxation times T 1 and T 2 are present.
Chemical shift δ is usually expressed in parts per million (ppm) by frequency, because it is calculated from [5] =, where ν sample is the absolute resonance frequency of the sample, and ν ref is the absolute resonance frequency of a standard reference compound, measured in the same applied magnetic field B 0.
This difference reflects the large magnetic moment of an electron (−1.00 μB), which is much greater than any nuclear magnetic moment (e.g. for 1 H: 1.52×10 −3 μB). Owing to rapid spin relaxation, the electron-nuclear coupling is not observed in the NMR spectrum, so the affected nuclear resonance appears at the average of the two coupled ...
Electron paramagnetic resonance (EPR) or electron spin resonance (ESR) spectroscopy is a method for studying materials that have unpaired electrons. The basic concepts of EPR are analogous to those of nuclear magnetic resonance (NMR), but the spins excited are those of the electrons instead of the atomic nuclei .