燃烧法合成La_2Zr_2O_7粉及其光谱性能

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。

Preparation of La2 Zr2 O7 Powder with Combustion Method and Its Spectral Properties

La2 Zr2 O7 powder was prepared with combustion method with La2 O3 ,Zr (NO3 )4 and glycine as raw materials. La2 Zr2 O7 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 La2 Zr2 O7 powders were studied.The X-ray diffraction pattern of La2 Zr2 O7 powder after heat treatment at 600 ℃ has one diffraction peak,and the diffraction peak is quite broad,therefore,the crystal structure of the La2 Zr2 O7 powder is semi-crystal structure.With the increase of heat treatment temperature,diffraction peaks become gradually sharp and increase.The crystal structure of the La2 Zr2 O7 powders after heat treatment in 750~800 ℃are pyrochlore structure.Analysis results of IR spectra of La2 Zr2 O7 powders after heat treatment in 650~750 ℃ show that the crystal structure of the La2 Zr2 O7 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 La2 Zr2 O7 powders show that the crystal structure of the La2 Zr2 O7 powders are stability in 120~1 600 ℃.