@article{oai:nitech.repo.nii.ac.jp:00004995, author = {Hayakawa, Tomokatsu and Nogami, Masayuki}, issue = {5}, journal = {JOURNAL OF APPLIED PHYSICS}, month = {Sep}, note = {By using the fluorescence line-narrowing technique, we observed a broad fluorescence band in the vicinity of a resonant line of the 5D0→7F0 transition in an Eu3+-doped SiO2 glass synthesized by a sol-gel process. The comparison with a similar line in an Al2O3-SiO2:Eu3+ sol-gel glass revealed the existence of a chemical cluster of Eu3+ and O2- in the tetrahedral SiO4 network. The broad fluorescence band was attributable to an energy migration among the Eu3+ ions for the site-selectively received excitation energy. Also, based on Yokota-Tanimoto’s energy diffusion model, the fluorescence decay curves for the 5D0→7F2 transition were closely correlated with the energy migration and gel-glass transformation. The gel-shrinkage and reduced interatomic distance between Eu3+ ions due to a thermal treatment at higher temperature definitely resulted in a decrease in the associated lifetime of the initial decay., application/pdf}, pages = {2200--2205}, title = {Energy migration of the local excitation at the Eu3+ site in a Eu-O chemical cluster in sol-gel derived SiO2:Eu3+ glasses}, volume = {90}, year = {2001} }