Glass Technology Laboratory, Central Glass and Ceramic Research Institute, (Council of Scientific and Industrial Research), 196 Raja SC Mullick Road, Kolkata 700 032, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2010 Feb;75(2):640-6. doi: 10.1016/j.saa.2009.11.032. Epub 2009 Nov 18.
Dichroic Sm(3+): Au-antimony glass nanocomposites are synthesized in a new reducing glass (dielectric) matrix (mol%) K(2)O-B(2)O(3)-Sb(2)O(3) (KBS) by a single-step melt-quench technique involving selective thermochemical reduction. X-ray diffraction (XRD) and selected area electron diffraction (SAED) results indicate that Au(0) nanoparticles are grown along the (200) plane direction. The transmission electron microscopic (TEM) image reveals the elliptical Au(0) nanoparticles having major axis range 12-17 nm. Dichroic behavior is due to elliptical shape of Au(0) nanoparticles of aspect ratio approximately 1.2. Au(0) NPs of concentration of 0.03 wt% (4.1 x 10(18)atoms/cm(3)) drastically enhances the intensity ( approximately 7-folds) of electric dipole (4)G(5/2)-->(6)H(9/2) red transition (636 nm) of Sm(3+) ions and then attenuates with further increase in Au(0) concentration. The magnetic dipole (4)G(5/2)-->(6)H(5/2) green (566 nm) and (4)G(5/2)-->(6)H(7/2) orange (602 nm) transitions remain almost unaffected by presence of nano Au(0). Local field enhancement (LFE) induced by Au(0) SPR and energy transfer (ET) from fluorescent Au(0)-->Sm(3+) ions are found to be responsible for the enhancement while reverse ET from Sm(3+)-->Au(0) and optical re-absorption due to Au(0) SPR for attenuation.
二向色性 Sm(3+)： Au-锑玻璃纳米复合材料在一种新的还原玻璃（介电）基质（摩尔%）K(2)O-B(2)O(3)-Sb(2)O(3)（KBS）中通过单步熔融淬火技术合成，涉及选择性热化学还原。X 射线衍射（XRD）和选区电子衍射（SAED）结果表明，Au(0)纳米颗粒沿（200）面方向生长。透射电子显微镜（TEM）图像显示出长轴范围为 12-17nm 的椭圆形 Au(0)纳米颗粒。二向色性是由于 Au(0)纳米颗粒的椭圆形形状，其纵横比约为 1.2。浓度为 0.03wt%（4.1x10(18)个原子/cm(3))的 Au(0) NPs 强烈增强了 Sm(3+)离子的电偶极子（4）G(5/2)-->(6)H(9/2)红跃迁（636nm）的强度（约 7 倍），然后随着 Au(0)浓度的进一步增加而减弱。磁偶极子（4）G(5/2)-->(6)H(5/2)绿光（566nm）和（4）G(5/2)-->(6)H(7/2)橙光（602nm）跃迁几乎不受纳米 Au(0)的存在影响。由 Au(0)SPR 引起的局域场增强（LFE）和荧光 Au(0)-->Sm(3+)离子的能量转移（ET）被发现是增强的原因，而 Sm(3+)-->Au(0)的反向 ET 和 Au(0)SPR 引起的光再吸收则导致衰减。
