Preparation and characterization of pyrochlore La_2Zr_2O_7 nanocrystals by stearic acid method

摘要

Pyrochlore La_2Zr_2O_7 nanocrystals with cubic structure were prepared by stearic acid combustion method using zirconium nitrate and lanthanum nitrate as raw materials, stearic acid as solvent and dispersant. The La_2Zr_2O_7 was characterized by XRD, Raman, FT-1R, BET, TEM, HRTEM and Emission/excitation spectra. The effect of thermal treatment temperature on crystal size of the nanocrystals was studied and a single phase of La_2Zr_2O_7 was completely formed at 900 ℃. The interplanar distances of d_(222) and d_(400) measured from the TEM images were 0.322 nm and 0.263 nm, respectively, coinciding with the theoretical values. Moreover, the strong fluorescent property of the La_2Zr_2O_7 was measured, with the maximum emission peak at ca. 389 nm upon excitation at ca. 324 nm.