中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 21 No. 3 March 2011 |
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. School of Chemistry and Materials Science, Guizhou Normal University, Guiyang 550001, China;
3. Department of Science and Technology, Guangxi University of Technology, Liuzhou 545006, China）
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.
Key words: pyrochlore structure; hydrothermal synthesis; growth mechanism; optical properties
