کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5401481 | 1392713 | 2011 | 6 صفحه PDF | دانلود رایگان |
Mn2+ activated ZnGa2O4 powder phosphors have been prepared by urea combustion route. Powder X-ray diffraction and scanning electron microscopy (SEM) techniques have been used to characterize the as-prepared and post-treated (900 °C, 3 h) phosphors. The morphology shows small particles, voids and pores, with non-uniform shapes and sizes. The EPR spectrum exhibits an intense resonance signal at gâ1.985 with a sextet hyperfine structure (hfs) besides a weak broad signal at gâ4.05 and a hump near gâ2.27. The gâ1.985 resonance is due to Mn2+ ions in an environment close to tetrahedral symmetry. The resonances at gâ4.05 and 2.27 are attributed to the rhombic surroundings of the Mn2+ ions. The spin concentration (N) and the paramagnetic susceptibility (Ï) are evaluated and discussed. It is observed that the intensity of the resonance signal at gâ1.985 increases with decrease in temperature obeying the Boltzmann law. Upon post treatment the intensity of the green emission (λem=528 nm,4T1â6A1 transition of Mn2+ ions) has been increased to 3.35 times and a red shift has been observed.
⺠The paper deals with the synthesis of ZnGa2O4:Mn phosphor by an easy combustion method. ⺠Upon post treatment the luminescence intensity of the green emission enhanced by 3.35 times. ⺠EPR results also support such an enhancement in the intensity of the resonance signals.
Journal: Journal of Luminescence - Volume 131, Issue 8, August 2011, Pages 1789-1794