There are number of factors beside the physical state of the sample, the nature of excitation radiation and types of the impurity ions in a phosphor. Less attention has been paid to the effect of fuels on host preparation in its final performance. Tb(0.5mol%) doped MgAl2O4 phosphors have been synthesised by solution combustion technique by using different fuel like carbohydrazide, hydrazine and urea and their photoluminescence (PL), thermoluminescence (TL) and mechanoluminescence (ML) properties have been studied. XRD result confirms formation of the phosphor. ML has been excited impulsively by dropping a load of mass 0.7 kg on to the phosphors from various heights. As the piston is dropped on to the sample, ML intensity initially increased with time attained an optimum value for a particular time then decreased again increases to a value than decreases and finally disappeared for all the samples. ML intensity increased with gamma doses given to the sample. PL emission spectrum showed characteristic emission of Tb3+ ions. Two distinct peaks were observed at around 140 oC and 300 oC in TL glow curve of all the samples. It is observed that urea enhances the luminescence properties of the MgAl2O4:Tb phosphor.
Photoluminescence, Mechanoluminescence, Thermoluminescence, Defects, Dislocations