Linewidths spectral splittings

Up to now, we have dealt only with the static effects of the spin-spin interactions. These effects are no longer observed when the splitting SB of the resonance lines due to these interactions is much smaller than the spectral linewidth or when the spin-lattice relax-... 

Several general observations can be made from the spectra and the calculated ESR parameters. First, the Na+- smectites possess narrower resonance line widths than the Ca +-smectites, with the exception of the saponite. Since Ca +-smectites, unlike Na+ -smectites, do not disperse into individual platelets in aqueous suspension, the Na+-smectite films formed by drying suspensions onto a smooth flat surface have the silicate surfaces more perfectly oriented in the plane of the film. As a result, less angular variation of the z-axis of Cu + relative to the plane of the film would narrow the spectra. One can see evidence of hyperfine splitting in the gj component of the Na+-smectite spectra, but not in the Ca +-smectite spectra. Saponite, unlike the other smectites, has very similar spectral linewidths for the Na+ and Ca + form (Figure 16). Since this Na+-saponite sample does not disperse completely in water (Table II), the alignment of Na+-saponite platelets in the clay film may be no better than that of the Ca +-saponite. 

With this technique the Doppler width could be reduced by two orders of magnitude below the natural linewidth, and spectral structures within the Doppler width could be resolved. Examples are the resolution of hyperfine structure components in an 12-beam using a single-mode argon laser (tunable within a few gigahertz) or the investigation of the upper state hfs-splitting in the atomic... 

Fig. 5. Energy level diagram for Pd(2-thpy)2 dissolved in n-octane. The Tj state at 18,418 cm is zero-field split on the order of 0.2 cm. The emission decay times refer to the individual triplet suhstates I, II, and III, respectively, at T = 1.3 K. (Compare Fig. 6.) These suhstates are radiatively deactivated as purely electronic transitions, as well as by Franck-Condon (FC) and Herzberg-Teller (HT) vibrational activity, respectively. This leads the different vibrational satellites. (Compare also Sects. 4.2.2 and 4.2.3.) The lifetime of the S, state is determined from the homogeneous linewidth of the spectrally resolved Sq —> S, electronic origin. (Sect. 3.2) The electronic state at 24.7 x 10 cm is not yet assigned...

Since the macroscopic polarizations are determined by optical coherences induced in the sample, their observation is restricted by Doppler dephasing, and the spectral resolution of the polarization beats is limited to the Doppler linewidths. In comparison with that quant am-beats are nearly imaffected by inhomogeneous broadening and therefore they are appropriate for high resolution level splitting measurements. 

Data were taken from Refs. 19,23,24,27, and 75. T is the temperature of measurement, S is the isomer shift related to metallic iron, A is the quadrupole splitting, Sq is the quadrupole shift, H is the hyperfine magnetic field, and F is the spectral linewidth. 

TABLE 26.1 Mossbauer spectral parameters - Isomer Shift (IS, mm/s), Quadrupole Splitting (QS, mm/s), Hyperfine field (HI, kOe) for polycrystalline samples prepared at FSU. Observed linewidth 0.29-0.35 mm/s... 

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