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Improved Cooperative Emission in Ytterbium‐Doped Oxyfluoride Glass‐Ceramics Containing CaF 2 Nanocrystals
Author(s) -
Imanieh Mohammad H.,
Martín Inocencio R.,
Eftekhari Yekta Bijan,
Marghussian Vahak K.,
Shakhesi Saeed
Publication year - 2012
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.12012
Subject(s) - materials science , crystallization , phase (matter) , analytical chemistry (journal) , microstructure , ytterbium , crystal (programming language) , mineralogy , chemical engineering , doping , composite material , chemistry , chromatography , organic chemistry , computer science , programming language , optoelectronics , engineering
The effect of alumina content and heat treatment time, on microstructure and cooperative emission of oxyfluoride glass‐ceramics were investigated. Two values (1.8 and 2.18) were selected for SiO 2 / Al 2 O 3 ratio. The results indicated that alumina content had a significant effect on the phase separation and the viscosity of the glasses. Although crystallization happened in the glass with SiO 2 / Al 2 O 3 ratio of 2.18 via spinodal decomposition phase separation, the other glass was crystallized in a homogeneous glass phase. Accordingly, the size and volume concentration of nano CaF 2 crystalline phase which precipitates during the heat treatment depends on the glass's alumina content. Furthermore, the crystal size was raised dramatically with duration of heat treatment time in the high‐containing aluminum oxide. In the other glass specimen, i.e., in the glass with a SiO 2 / Al 2 O 3 ratio of 2.18, only a slight increase in the crystal size was observed by raising the heat treatment time. Increasing the time of heat treatment led to the incorporation of Yb 3+ ions into CaF 2 crystalline phase. Moreover, cooperative emission coming from a pair of excited Yb 3+ ions was obtained and increased significantly with the heat treatment time. The results showed that the optimum heat treatment time was 48 h.