铕离子探针研究Al_2O_3的相变过程

The Phase Transition in Alumina Studied by Eu^(3+) Ion Probe

Because of industrial interest, techniques to prepare a thermally stabilized active alumina have been developed. Ionic probe has been widely used in the studying of structure and function on biomacromolecules. In this paper, the phase transition in alumina at differ-ent sintering temperatures was first studied by Eu3+ ion fluorescent probe. The XRD, FTIR and fluorescence spectra measurements show that γ-phase is dominated in alumina at below 1000℃; the mixed γ-and phases in the sample are produced at 1 100 ℃;but α-phase in alumina is dominated at 1 200 ℃. It is shown in FTIR spectra that the peak of Eu-O stretching vibration increases dramatically at 1 200 ℃ Meanwhile, fluorescence spectra in-dicate that the peak of 613 nm is weakned gradually whereas the peak of 617 nm is strength-ened in 5D0-F2 supersensitive transition of Eu3+ when the sintering temperature increases.However, the peak of 5D0-7F4 transition splits evidently at 1 200 ℃ because of the decreasing of symmetry in Eu3+ coordination site.