Univ Sci & Technol China, Natl Lab Synchrotron Radiat, Hefei 230029, Peoples R China
; Univ Sci & Technol China, Dept Phys, Hefei 230026, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
; Capital Normal Univ, Dept Phys, Beijing 100037, Peoples R China
Chemical coprecipitated amorphous and nanocrystalline ZrO2.Y2O3 (15%) was Studied by Powder X-ray diffraction(XRD) and extended X-ray absorption fine structure(EXAFS). XRD result shows that the sample is an amorphous phase annealed below 300 degreesC; and it crystallizes into cubic nanocrystalline zirconia at 500 degreesC. EXAFS analysis indicates that the coordination number and bond length of Zr-O shell has not changed when transforming from amorphous into nanocrystalline. This suggests that at 300 degreesC,it has formed the same nearest-neighbor local structure as at 900 degreesC. For Zr-Zr(Y) shell, with the reducing of grain size, the coordination number decreases obviously: the bond length is shorter and the disorder becomes larger. This result suggests that the grain size effect is much stronger for more distant coordination shell (Zr-Zr) than for the first nearest-neighbor shell(Zr-O).