Nucleus magnetic moment

Often in tables the values describing a nucleus magnetic moment are represented as lying upon an axis parallel to B, the applied magnetic field. Therefore, if for a proton, /x — 1.41 x 10-26 J T l, calculate the constant 7 for the proton. 

NMR is not an explicitly surface - sensitive technique, but NMR data on large surface area samples (> 1 m2) have provided useful data on molecular adsorption geometries. The nucleus magnetic moment interacts with an externally applied magnetic field and provides spectra highly dependent on the nuclear environment of the sample. The signal intensity is directly proportional to the concentration of the active species. This method is limited to the analysis of magnetically active nuclei. 

Here Ti is the spin-lattice relaxation time due to the paramagnetic ion d is the ion-nucleus distance Z) is a constant related to the magnetic moments, i is the Larmor frequency of the observed nucleus and sis the Larmor frequency of the paramagnetic elechon and s its spin relaxation time. Paramagnetic relaxation techniques have been employed in investigations of the hydrocarbon chain... 

The " N nucleus (/ = 1, 99%) has a moderately large magnetic moment and hyperfine splittings from this nucleus are a distinctive feature of the EPR spectra of chalcogen-nitrogen radicals. A-Arylthio-2,4,6-triphenylanilino radicals (3.16) are exceptionally persistent and oxygen-insensitive m solution. They exhibit a characteristic 1 1 1... 

A nucleus having spin generates a magnetic moment pi. which is proportional to the angular momentum. Theory is not capable of calculating pi, so it is commonly expressed as Eq. (4-42), where 7 is called the magnetogyric ratio. 

An intuitive model of the process can be given. Consider the proton, with / = i then there are two states, characterized by m = +5 and m = —5. In the absence of an applied field, these states are equally populated. The states may be pictured as corresponding to opposite orientations of a tiny bar magnet, which is a crude way of visualizing the magnetic moment vector. Clearly in the absence of an applied field, the orientation of the moment should not affect the energy of the nucleus. 

Consider a nucleus with magnetic moment pi in a magnetic field Ho- According to classical mechanics the rate of change of the angular momentum G is the torque T. 

Here Iais the magnetic moment of nucleus A and Ra is the position (the nucleus is the natural Gauge origin). Adding this to the external vector potential in eq. (10.62) and expanding as in (10.63) gives... 

On the other hand, internal magnetic fields at the iron nucleus arising from the magnetic moments of unpaired valence electrons can be much stronger than any applied field and their effect can easily exceed the quadrupole interaction. For instance, Mossbauer nuclei in magnetic materials such as metals or oxides may experience fields of 30-50 T even without applied field. Similarly, the typical... 

Atoms are observed to have magnetic moments. To understand how an electron circulating about a nuclear core can give rise to a magnetic moment, we may apply classical theory. We consider an electron of mass me and charge —e bound to a fixed nucleus of charge Ze by a central coulombic force F(r) with potential V(r)... 

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