燃烧法合成La2Zr2O7粉及其光谱性能

Preparation of La_2Zr_2O_7 Powder with Combustion Method and Its Spectral Properties

以La_2O_3,Zr（NO_3）_4和甘氨酸为原料,采用燃烧法合成La_2Zr_2O_7粉。分别用发射光谱法（ICPAES）、能谱法（EDAX）、X衍射法（XRD）、红外光谱法（IR）和热重-差热法（TG-DTA）等对La_2Zr_2O_7粉进行表征。分别研究了热处理温度对La_2Zr_2O_7粉的X衍射谱和红外光谱的影响。La_2Zr_2O_7粉的ICP-AES和EDAX分析结果表明,用燃烧法可合成出La_2Zr_2O_7粉。不同温度热处理后La_2Zr_2O_7粉的XRD分析结果表明,当热处理温度为600℃时,出现一个衍射峰,且衍射峰较宽,该结构为半晶型结构;提高热处理温度,衍射峰逐渐尖锐,峰形变窄,衍射峰逐渐增多;热处理温度在750~800℃范围,可得到烧绿石结构的La_2Zr_2O_7粉。在650~750℃热处理后La_2Zr_2O_7粉的红外光谱分析结果与XRD分析结果相同,热处理温度为750℃时,可得到烧绿石结构的La_2Zr_2O_7粉。La_2Zr_2O_7粉的TG-DTG分析结果表明,在120~1 600℃范围,La_2Zr_2O_7粉的结构稳定。

La_2Zr_2O_7 powder was prepared with combustion method with La_2O_3,Zr（NO_3）_4 and glycine as raw materials.La_2Zr_2O_7 powders were characterized with ICP-AES,EDAX,XRD,IR and TG-DTA techniques,respectively.Effects of heat treatment temperature on the XRD spectra and IR spectra of La_2Zr_2O_7 powders were studied.The X-ray diffraction pattern of La_2Zr_2O_7 powder after heat treatment at 600 ℃ has one diffraction peak,and the diffraction peak is quite broad,therefore,the crystal structure of the La_2Zr_2O_7 powder is semi-crystal structure.With the increase of heat treatment temperature,diffraction peaks become gradually sharp and increase.The crystal structure of the La_2Zr_2O_7 powders after heat treatment in 750~800 ℃are pyrochlore structure.Analysis results of IR spectra of La_2Zr_2O_7 powders after heat treatment in 650~750 ℃ show that the crystal structure of the La_2Zr_2O_7 powders after heat treatment at 750℃is pyrochlore structure,and the analysis results of XRD and IR are the same.Analysis results of TG-DTG of La_2Zr_2O_7 powders show that the crystal structure of the La_2Zr_2O_7 powders are stability in 120~1 600 ℃.