纳米晶Gd2O3：Eu^3＋的制备及发光性能

采用低温燃烧合成法制备了Gd2O3：Eu^3＋纳米晶。用X射线衍射仪（XRD）、高分辨透射电子显微镜（HRTEM）和荧光光谱仪分别对样品的结构、形貌和发光性能进行了研究。结果表明，改变甘氨酸与稀土离子的比例（G／M）、退火温度可以制备出不同结构和晶粒尺寸的Gd2O3：Eu^3＋纳米晶。在退火温度为800℃，G／M等于0．83和1．0时，均得到了纯立方相的Gd2O3：Eu^3＋纳米晶，随着G／M的增加，Gd2O3：Eu^3＋从立方相逐渐向单斜相转变。粉末的晶粒尺寸随着退火温度的增高而增大，晶粒尺寸在10-30nm之间。立方相的Gd2O3：Eu^3＋纳米晶主发射峰位置在612nm（^5D^0→^7F2跃迁），激发光谱中电荷迁移态发生了红移。

Preparation and luminescence properties of nanocrystals Gd2O3: Eu3+]

Nanocrystalline Gd2O3 doped with europium was synthesized by the low-temperature combustion method. By using the X-ray diffraction (XRD), high resolution transmission electron microscopy( HRTEM), and fluorescence spectrophotometer, the structural, morphological and luminescence properties of the nanocrystal were investigated. The results show that by varying the glycine-to-metal nitrate (G/M) molar ratio and the annealing temperature, nanocrystalline Gd2O3: Eu3+ with different structure and grain size could be achieved. The structure changed from cubic to monoclinic with the increment of G/M ratio after the samples had been calcined at 800 degrees C for 0.5 hour. When the G/M ratio was 0.83 and 1.0, the nanosized and pure cubic phase Gd2O3: Eu3+ was produced. The crystalline size became bigger with increasing the annealing temperature. The grain size was about 10-30 nm. The main emission peak in cubic Gd2O3: Eu3+ nanocrystal was at 612 nm(the (5)D0-->F2 transition). In addition, a red shift for charge transfer state occurred in the excitation spectrum.