Raman光谱(拉曼光谱)第四章4-3-左健-理化中心课件

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,*,提出的,ZrO,2,相变机理,UV Laser,X-ray,UV Raman Scattering,XRD,Visible Laser,Visible Raman Scattering,Amorphous Zr(OH),4,Tetragonal ZrO,2,Monoclinic ZrO,2,紫外拉曼光谱与,XRD,，,可见拉曼光谱结果的不同表明氧化锆四方相到单斜相的相变首先是从表面开始，接着逐步发展到体相。,S. Shukla,et al.,Nano Letters,2002, 2, 989.,TEM evidence for the phase transformation of ZrO,2,Tetragonal Monoclinic,Can Li, et al.,J. Phys. Chem. B,2001, 105, 8107.,2 mol %Y,2,O,3,-ZrO,2,体相主要为四方相,掺杂,2 mol%,Y,2,O,3,并不能使四方相在样品的表面稳定,整个焙烧过程中仅观察到单斜相谱峰,Y,掺杂氧化锆相变的研究,紫外，近紫外拉曼光谱图和,XRD,图谱,5 mol %Y,2,O,3,-ZrO,2,体相主要是四方相,表面主要是单斜相,紫外和近紫外拉曼光谱图,8 mol %Y,2,O,3,-ZrO,2,表面处于扭曲结构的单斜晶相,体相处于四方晶相,Monoclinic,Tetragonal,400,500,600,700,800,Calcination Temperature/,o,C,Surface phase,Bulk phase,2 wt% Y,2,O,3,400,500,600,700,800,Calcination Temperature/,o,C,8 wt% Y,2,O,3,Distorted surface phase,Y,掺杂氧化锆相变的过程,Amorphous,Tetragonal,Monoclinic,ZrO,2,400 500 600 700 800,Calcination Temperature /,o,C,8 mol% Y,2,O,3,-ZrO,2,8 mol% La,2,O,3,-ZrO,2,t m,ZrO,2,及,Y,2,O,3,(La,2,O,3,)-,ZrO,2,相变,TiO,2,的晶相结构,ZrO,2,的晶相配位结构,Rutile,Anatase,Brookite,rutile anatase brookite,TiO,2,TiO,2,TiO,2,-Form.Wt. 79.890 79.890 79.890,Crystal System Tet Tet Orth,Space Group P42/mnm I41/amd Pbca,Unit Cell,a() 4.5845 3.7842 9.184,b() 5.447,c() 2.9533 9.5146 5.145,Vol 62.07 136.25 257.38,MolarVol 18.693 20.156 19.377,Density 4.2743 3.895 4.123,锐钛矿和金红石相的,UV-,vis,和拉曼光谱图,532 nm,244 nm,325 nm,TiO,2,不同温度焙烧的,XRD,图谱和可见拉曼光谱,可见拉曼的结果与,XRD,的结果,一致,混合晶相,金红石晶相,TiO,2,不同温度焙烧的紫外和可见拉曼光谱,Phase transformation of TiO,2,calcined in air at different temperatures,Rutile,Anatase,300,500,400,700,800,Calcination Temperature/,o,C,Surface phase,Bulk phase,600,500,o,C,(,锐钛矿,),600,o,C,(,锐钛矿和金红石,的混合晶相,),800,o,C,(,金红石,),不同温度焙烧的,TiO,2,样品的,TEM,小粒子团聚成大粒子,TiO,2,相变模型,400 500 600 700 800,Calcination Temperature /,o,C,Anatase,Rutile,Anatase,Rutile,UV Raman spectra,UV laser,visible Raman spectra,visible laser,