Spectroscopic splitting factor

Three basic equations (3.10-3.12) are needed to describe the technique. In the equations, p is the magnetic moment of the electron, sometimes also written as pe, g is called the g factor or spectroscopic splitting factor, S is defined as the total spin associated with the electron (in bold type because it is considered as a vector), B is the imposed external magnetic field (also defined as a vector quantity), and... 

If a free-atom state (Section 6.3.3) is subject to a magnetic field the (2J + l)-fold degeneracy is lifted so that, as shown in Figure 27, each level specified by the quantum number My is separated from its neighbour by the amount gjpH, where gj is the spectroscopic splitting factor. The value of g can be calculated from a knowledge of the term from which the state arose. 

The spectroscopic splitting factor g that is determined from resonance experiments must be distinguished from the g factor determined by gyromagnetic experiments (347,526,632). In a gyromagnetic experiment (Einstein-DeHaas (164) or Barnett (40) methods), what is measured is the magnetomechanical ratio (see eq. 73)... 

If the orbital angular momentum is quenched by the crystalline fields, so that e is small, then it is possible to show (347) that for a resonance experiment the spectroscopic splitting factor g is given by... 

In the case of the transition element atoms or ions, the orbital angular momentum is usually quenched, and it has become customary to define the spectroscopic splitting factor g by equation 81 rather than by equation 13. Then equation 20 becomes... 

One of the striking successes of the N< el model was its ability to account for the magnetization curves of the zinc-substituted ferro-spinels shown in Figure 23, where nB = Mq/N hb is the number of Bohr magnetons per molecule. From the intercept at x = 0, it is theoretically possible to obtain the spectroscopic splitting factor, as defined by equation 81. However, the discrepancies shown in Table IX between the original measurements by Guillaud et al. (243) and... 

ESR parameters Humic acid Chlorophenoxy compounds Free radical concentration (spins 10 ) Line width (gauss) Spectroscopic splitting factor (g — values) ... 

The g value (spectroscopic splitting factor), a very important ESR spectral parameter that is sensitive to the molecular environment of an unpaired electron, unfortunately was treated only casually in early coal studies. The utility of the parameter in coal research is becoming more apparent as more precise values become available. A plot of the ESR g... 

ESR Spectra. The question had been raised as to what type of polymerization mechanism was involved. We propose a free-radical process on the basis of the analogy between the cyclic bis(arylene tetra-sulfides) and sulfur itself. To resolve this point, the polymerization of monomer I, in bulk, was carried out in the cavity of an ESR spectrometer. The ESR signal shown in Figure 1 clearly demonstrates a free-radical mechanism, and the g-value (spectroscopic splitting factor) of 2.023 for the free radicals formed during polymerization agrees closely with the g-value of 2.024 reported for polymerization of sulfur (24). 

Trapped electrons were identified by ESR at very low microwave power in polyethylene (Marlex and Alathon) after 7-irradiation at —198°C (Fig. 26) [141]. The spectroscopic splitting factor was found to be g = 2.0022 0.0002. 

The constant of proportionality g equals 2.0023 for a free electron and is called the spectroscopic splitting factor, or just the g factor. It is equivalent to the Lande g factor of atomic spectroscopy. 

The spectroscopic splitting factor g is given by the Land6 formula. 

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