【摘要】 采用水热法在180oC下反应36h合成了具有规整八面体状的烧绿石结构La2Sn2O7:Eu3+微晶。采用XRD、TEM、SEM、EDS、FT-IR、Raman和PL对合成产物的晶体结构、颗粒尺寸、形貌和光学性能进行了研究。对前驱体溶液的pH值、前驱体浓度、水热反应温度和水热反应时间等工艺条件的影响进行了研究。研究结果证实前驱体溶液的pH值不仅决定合成产物的物相结构,而且对合成产物的形貌也具有显著的影响。在pH值为12时可以获得平均尺寸为700nm的规整八面体状晶体。提出了八面体状La2Sn2O7:Eu3+微晶的可能形成机理。光致发光光谱显示:八面体状La2Sn2O7:Eu3+微晶与其它形貌的样品相比较,在582-592nm区域具有更强的发光强度。更多还原

【Abstract】 Pyrochlore structure La2Sn2O7:Eu3+ microcrystals with uniform octahedron shape were successfully synthesized via a hydrothermal route at 180 °C for 36 h. The crystal structure, particle size, morphologies, and optical properties of the as-synthesized products were investigated by XRD, TEM, SEM, EDS, FT-IR, Raman spectroscopy and PL. The effects of pH of precursor solution, precursor concentration, reaction temperature, and time were investigated. The results reveal that pH of the precursor solution not only plays an important role in determining the phase of the as-synthesized products, but also has a significant influence on the morphologies of the samples. High-quality and uniform octahedrons with an average size of about 700 nm could be easily obtained at the pH value of 12. The possible formation mechanism of octahedral-like La2Sn2O7:Eu3+ microcrystals was briefly proposed. The photoluminescence spectra show that La2Sn2O7:Eu3+ micro-octahedra display stronger emission in the range of 582-592 nm compared with the samples with other shapes.更多还原