【摘要】 采用柠檬酸作燃烧剂用燃烧合成法制备了Gd2O3:Eu3+纳米晶.用X射线衍射仪(XRD)、高分辨透射电子显微镜(HRTEM)和荧光分光光度计等对Gd2O3:Eu3+纳米晶的结构、形貌和发光性能进行了分析.结果表明:不同柠檬酸与稀土离子配比(C/M)制备的样品经800℃退火1h后,均得到了纯立方相的Gd2O3:Eu3+纳米晶,晶粒尺寸约为30nm,尺寸分布较窄,其中以C/M=1.0时制备的纳米晶结晶性最好,发光强度最大.Gd2O3:Eu3+纳米晶主发射峰位置均在612nm处(5D0→7F2跃迁),激发光谱中电荷迁移态发生红移,观察到Gd3+向Eu3+的有效能量传递.对柠檬酸与稀土离子配比(C/M)对结晶度、发光性质等的影响也进行了分析和讨论.更多还原

【Abstract】 Nanocrystalline Gd₂O₃:Eu 3+ was prepared by modified combustion synthesis using citric acid as the fuel and metal nitrates as oxidants. By using X-ray diffraction （XRD）,high resolution transmission electron microscopy （HRTEM） and fluorescence spectrophotometry, the structural, morphological and luminescent properties of the nanocrystals were investigated. The results showed that Gd₂O₃:Eu 3+ nanocrystal with pure cubic phase was produced after the samples prepared using different citric acid-to-metal nitrate （C/M） molar ratios were calcined at 800℃ for 1 hour. The grain size was approximately 30 nm and the size distribution was narrow. The Gd₂O₃:Eu 3+ nanocrystals whit C/M ratio 1.0 had the best crystallinity and strongest photoluminescence. The main emission peak of Gd₂O₃:Eu 3+ nanocrystal was 612 nm, being attributed to ⁵D₀→ ⁷F₂ transition. The charge transfer state had an obvious red shift in the excitation spectrum. The efficient energy transfer from Gd 3+ to Eu 3+ was also observed. In addition, the influences of C/M molar ratio on crystallinity and luminescent properties were studied and discussed.更多还原