Radiation damage of MnO−4 ions in (NH4)2SO4 single crystals

The radiation damage of MnO doped ammonium sulphate single crystals is studied. The optical absorption spectra of these crystals before irradiation consist of absorption bands around 5200, 3400, 3000, and 2300 Å. These bands are found to decrease in intensity on irradiation with the simultaneous growth of new bands around 7900, 5600, 4200, 3300, and 2900 Å. These newly produced bands are attributed to the formation of MnO ions. The spin-unrestricted SCF cluster model given by Johnson and Smith in conjunction with the Slater's transition state theory is used to interpret the observed spectra of both MnO and MnO ions. The possible kinetics of radiolysis is discussed.