Mossbauer spectroscopy further possibilities

Platinum ammine complexes have been a fertile area for studying transinfluence. Table 3.21 lists data for a range of ammines showing how /(195Pt-15N) depends upon the trans-atom [153]. (A further selection of data can be found in R.V. Parish, NMR, NQR, EPR and Mossbauer Spectroscopy in Inorganic Chemistry, Ellis-Horwood, Chichester, 1991, pp. 76, 87.) Possibly the most detailed study (of complexes of tribenzylphosphine) examined over a hundred neutral and cationic complexes [154] (Table 3.22). 

This chapter has presented a review of the parameters involved in Mossbauer spectroscopy within the context of phase transformations. Although the Mossbauer effect can be considered a mature technique, now more than forty years old, technical developments continue to expand the experimental possibilities. Spatial resolution has improved within the last decade. The development of the Mossbauer milliprobe, for example, has enabled spatial resolution to be increased by more than two orders of magnitude (McCammon et al. 1991, McCammon 1994). Further improvement of spatial resolution may be anticipated with advances in nuclear forward scattering. Other possibilities on the horizon include development of a Mossbauer electron microscope which would focus conversion electrons using conventional electron optics (Rancourt and Klingelhofer 1994). 

In carrying out calculations for multi-site mixing such as this, you can either use equation (15.10) directly, or work through the problem stepwise and ion by ion as with (15.8) the two methods are equivalent. Further details are given by Powell (1977). It is possible using analytic techniques such as X-ray diffraction, Mossbauer spectroscopy and infra-red, Raman and UV-visible spectroscopy to analyze for the concentration of different ions on specific crystal sites. Thus the activities, configurational entropies, and other such properties of solid solutions can often be calculated. This provides detailed information on the stability and structure of crystalline solutions. 

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