An assessment of thermal behaviour and gamma radiation stability of lanthanide-doped aluminium phosphate glasses for immobilization of minor actinides

The effects of lanthanides addition (Ce, Pr, Nd and Gd) to aluminium phosphate glass on its thermal properties were systematically studied. It was observed that the temperature of the glass transition gets enhanced due to the increase in the rigidity of the network upon doping. The fragility index values (m = 22–40) of lanthanide-doped glasses indicated their strong glass-forming ability. The specific heat capacity values showed a monotonous variation with the lanthanide content. Ce- and Pr-doped glasses showed maxima in heat capacity at 5 wt% and minima at 10 wt% doping, whereas Nd- and Gd-doped glasses showed maxima at 3 wt% and minima at 10 wt% doping. The DSC curve of the 10 wt% lanthanide-doped glasses showed exothermic peaks in the range 913–920 K, is due to the formation of a monazite phase. The FTIR spectra of the γ-irradiated glass specimens evidenced the structural stability of these glasses.