Department of Physics, Acharya Nagarjuna University - Nuzvid Campus, Nuzvid 521 201, AP, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2012 Feb;86:472-80. doi: 10.1016/j.saa.2011.10.071. Epub 2011 Nov 4.
The glasses of the composition 19Na(2)SO(4)-20MO-60P(2)O(5): 1.0Ho(2)O(3)/1.0Er(2)O(3) (M=Mg, Ca, and Ba) have been synthesized. Optical absorption and fluorescence spectra (in the spectral range 350-2100 nm were studied at ambient temperature. The spectra were characterized using Judd-Ofelt theory. From the luminescence spectra, various radiative properties like transition probability A, branching ratio β and the radiative life time τ for blue (B), green (G) and red (R) emission levels of these glasses have been evaluated. The energy transfer between the two rare earth ions (Ho(3+) and Er(3+)) in co-doped Na(2)SO(4)-MO-P(2)O(5) glass systems in the visible and NIR regions has also been investigated. Highest intensity, the highest quantum efficiency and maximum energy transfer with low phonon losses of B, G, and R lines has been observed in BaO mixed glasses. The reasons for such higher values of these parameters have been discussed in the light of varying field strengths at the rare earths ion site due to replacement of one modifier oxide with the other. The enhanced intensity of NIR emission (at 2.0 μm) has also been discussed in terms of cross relaxation of Er(3+) ions from (4)I(13/2) level to (5)I(7) of Ho(3+) ions.
该组合物的玻璃 19Na(2)SO(4)-20MO-60P(2)O(5): 1.0Ho(2)O(3)/1.0Er(2)O(3)（M=Mg、Ca 和 Ba）已经合成。在环境温度下研究了光学吸收和荧光光谱（在 350-2100nm 光谱范围内）。使用 Judd-Ofelt 理论对光谱进行了表征。从发光光谱中，评估了这些玻璃的蓝色（B）、绿色（G）和红色（R）发射能级的各种辐射性质，如跃迁概率 A、分支比 β 和辐射寿命 τ。还研究了在可见和近红外区域共掺杂 Na(2)SO(4)-MO-P(2)O(5)玻璃系统中两个稀土离子（Ho(3+)和 Er(3+)）之间的能量转移。在 BaO 混合玻璃中观察到 B、G 和 R 线的强度最高、量子效率最高和能量转移最高，且声子损耗最低。根据稀土离子位点的场强因替代一个调节剂氧化物而发生变化，讨论了这些参数值较高的原因。还根据 Er(3+)离子从（4）I(13/2)能级到 Ho(3+)离子的（5）I(7)能级的交叉弛豫，讨论了近红外发射（在 2.0μm 处）的增强。
