Pentavalent ions spectra

In contrast to the case of divalent Co-57 ions described above, the spectra show no hysteresis against the lowering of pH. Conversely, the spectrum of a sample previously adjusted to a pH of 2.5 was found to remain broadened after the pH had been raised to 8.6 (Figure 5(F)). Thus, the chemical structure of pentavalent Sb-119 adsorbed from an acidic solution is considered to be retained when the pH of the solution is raised above 7. 

Sb carrier ions. The Sb-119 ions were adsorbed on 30 mg of hematite from 10 cm3 of a 0.25 mol/dm3 KC1 solution containing about 1 mg of pentavalent Sb ions. About 0.3 mg of Sb was adsorbed at pH 2.5 and 4.0. The amounts of Sb adsorbed are less than that required to cover all the hematite surfaces as a monolayer. The emission Mossbauer spectra obtained are shown in Figure 7. It is seen from Figure 7 that the width of the emission Mossbauer spectrum at pH 2.5 is much smaller than that of the carrier-free one, while essentially no effect of carrier Sb ions is observed at pH 4.0. 

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