Study on structural variation of silica gel using Nd3+ as a probe by photoacoustic spectroscopy.
The structural variations of silica gels heated at different temperatures have been firstly studied using Nd(3+) as a probe by photoacoustic spectroscopy (PAS), together with IR spectroscopy and thermal analysis. With increasing temperature, the f-f transitions of Nd(3+) show a red shift and the PA intensities increase. The PA branching vector of the transitions from ground state to 4G(5/2)+(2)G(7/2), which are hypersensitive transitions, increase and the others decrease or change little. These indicate that the covalency of the bond that Nd(3+) forms increases and the symmetry around Nd(3+) decreases, which reflects the structural variations of silica gels.
Department of Chemistry, University of Science and Technology of China, Hefei Anhui 230026, PR China.
Wu
W
Ronghu
Yu
Y
Xijuan
Song
S
Huiyu
Su
S
Qingde
D000162:Acoustics; D009354:Neodymium / Q000737:chemistry*; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*; D013053:Spectrophotometry; D013055:Spectrophotometry, Infrared; D013057:Spectrum Analysis; D013499:Surface Properties; D013816:Thermodynamics
D009354:Neodymium; D058428:Silica Gel; D012822:Silicon Dioxide