Department of Physics, Manipur University, Canchipur, Imphal-795003, Manipur, India.
Dalton Trans. 2012 Apr 21;41(15):4404-12. doi: 10.1039/c2dt12190e. Epub 2012 Feb 15.
GdVO(4) : Ln(3+) (Ln(3+) = Dy(3+), Eu(3+), Sm(3+), Tm(3+)) nanoparticles are prepared by a simple chemical route at 140 °C. The crystallite size can be tuned by varying the pH of the reaction medium. Interestingly, the crystallite size is found to increase significantly when pH increases from 6 to 12. This is related to slower nucleation of the GdVO(4) formation with increase of VO(4)(3-) present in solution. The luminescence study shows an efficient energy transfer from vanadate absorption of GdVO(4) to Ln(3+) and thereby enhanced emissions are obtained. A possible reaction mechanism at different pH values is suggested in this study. As-prepared samples are well dispersed in ethanol, methanol and water, and can be incorporated into polymer films. Luminescence and its decay lifetime studies confirm the decrease in non-radiative transition probability with the increase of heat treatment temperature. Re-dispersed particles will be useful in potential applications of life science and the film will be useful in display devices.
GdVO(4)：Ln(3+)（Ln(3+) = Dy(3+)、Eu(3+)、Sm(3+)、Tm(3+)）纳米粒子通过在 140°C 下的简单化学途径制备。通过改变反应介质的 pH 值可以调整晶粒度。有趣的是，当 pH 值从 6 增加到 12 时，晶粒度显著增加。这与溶液中存在的 VO(4)(3-)增加导致 GdVO(4)形成的成核速度减慢有关。发光研究表明，GdVO(4)的钒酸盐吸收有效地将能量转移到 Ln(3+)，从而获得增强的发射。在这项研究中提出了在不同 pH 值下的可能反应机制。在乙醇、甲醇和水中制备的样品具有良好的分散性，并可掺入聚合物薄膜中。发光及其衰减寿命研究证实，随着热处理温度的升高，非辐射跃迁概率降低。再分散的颗粒将在生命科学的潜在应用中有用，而薄膜将在显示设备中有用。
