Influence Of Crystallization On The Conversion Of Sm~(3+)-+Sm~(2+) In Sro-Bi_2O_3-K_2O-B_2O_3 Glass-Ceramics

摘要

Sm~(3+)-doped glass 13SrO-2Bi_2O_3-5K_2O-80B_2O_3 was fabricated by the conventional melt-quenching technique. The glass-ceramics were obtained by heating the as-prepared glasses in air atmosphere at selected temperatures 550℃, 600℃, 615℃, and 650℃, respectively. The luminescence spectra of both Sm~(3+) and Sm~(2+) were detected in the ceramic heated at 650℃ where crystalline phase is formed. The as-prepared glass and the ceramics heated at 550℃, 600℃, and 615℃ show only the emission due to Sm~(3+). In the sample heated at 650℃ in air atmosphere, however, part of Sm~(3+) ions was converted to Sm~(2+), giving rise to sharp emission lines which are characteristic of Sm~(2+) in crystalline state. It is suggested that Sm~(2+) ions are located at Sr~(2+) site in the ceramic while Sm~(3+) ions are located at Bi~(3+) sites. The Sm~(2+)-doped glass-ceramic has a high optical stability because the fluorescence intensity decreases by only about 8% of its initial value upon excitation at 488 nm Ar~+ laser.