High Speed Preparation of GdCaAl3O7:Eu Nano-Phosphors by Microwave-Assisted Combustion Approach

G dCaAl3O7:Eu red nano-phosphors were synthesized by solution combustion using urea as fuel. Fourier-transform infrared, X-ray diffraction, scanning electron microscope, transmission electron microscope and photoluminescence spectrophotometer were used to characterize the obtained samples. XRD patterns revealed that GdCaAl3O7:Eu pure phase was formed by combustion of metal nitrate solution in the presence of urea at pH= 1 without further calcination step. Further increase of pH values resulted in the formation of impure GdAlO3 phase. Moreover, for a constant pH, fuel to oxidizer variations did not affect the structure of the samples. Morphological studies revealed that flake like structure has changed to spongy like by increasing the pH value of metal nitrate solution from 1 to 4. Photoluminescence properties of obtained samples showed that at pH =1 emission ranging from 580-630 nm is observed. The characteristic peaks at 595 nm and 615 nm can be assigned to and transitions, respectively. Prog. Color Colorants Coat. 3(2010), 110-117. © Institute for Color Science and Technology.