Nuclear Zeeman splitting

Quadrupole coupling, isomer shift Quadrupole tensor, nuclear Zeeman splitting, g values, coupling constants, relaxation times... 

Besides a strongly coupled proton with a nearly isotropic hfc of Ah —20 MHz, two clearly separated nitrogen peaks between 15-26 MHz with unresolved quadrupole and nuclear Zeeman splittings have been observed along all three turning points of the g tensor (Fig. 39b). In the evaluation of the hf data collected in Table 12.1 it is assumed that the two metal-coordinated 14N exhibit roughly axial hfs tensors with the Ajj1 values oriented approximately perpendicular to each other. 

The number of possible alignments of a magnetically active nucleus, when placed into a magnetic field is 21+1. This type of splitting of energy states is commonly referred to as nuclear Zeeman splitting. 

The Mossbauer effect is sensitive to the oxidation and spin state of iron and the environment around the iron nucleus therefore different chemical species yield different Mossbauer spectra. Furthermore all spin states and oxidation states of iron are accessible to the technique. There are three main components of a Mossbauer spectrum. The isomer shift arises from the electron density at the 57Fe nucleus the quadrupole splitting results from the electric field gradient produced by electrons and ions around the 57Fe nucleus, and the nuclear Zeeman splitting is sensitive to the spin state and magnetic coupling of the iron. 

Nuclear shielding reflects changes to the nuclear Zeeman splitting by an external magnetic field and is phenomenologically defined by eq. 1, where the effective magnetic field at the position of the nucleus in question is modified relative to the external field B by the shielding constant (tensor) a. 

This type of splitting of energy levels in magnetic fields for a nucleus (1 > 0) is called nuclear Zeeman splitting. 

As shown by Eq. (25.77), the energy levels produced by the nuclear Zeeman splitting can be expressed as a product containing the nuclear magnetic moment fi and the magnetic flux density, B, existing at the site of the nucleus. 

Figure 8. Level (anti-)crossing of nuclear sublevels S=l/2, 1=1 by adjusting the nuclear Zeeman splitting. Only the m=l transitions are shown in the diagram. As in Figure 7, the ENDOR transitions are mobile and subject to a critical point as the magnitude of the nuclear zeeman energy assumes a value that leads to the crossing condititm in (me electrcm spin...

Fig. 1.6 Shift and splitting of nuclear levels of nucleus by the hyperfine interactions and expected Mossbauer spectra, a Center shift of the observed absorption line. In this case the observed shift is the sum of isomer shift and second order Doppler shift, b Electric quadrupole splitting AEq and c magnetic h5 perfine splitting that is a nuclear Zeeman splitting. is the magnitude of the hyperfine magnetic field at nucleus...

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