Phase separation and crystallization processes in heat treatment of Mn4+-doped 90GeO(2)-10BaO glass and fluorescence properties

作者：Wada Noriyuki^*; Fujita Kenji; Inoue Koji; Kojima Kazuo

来源：Surface and Coatings Technology, 2015, 271: 127-135.

DOI：10.1016/j.surfcoat.2014.12.068

• Glass-ceramics
• Crystallization
• Phase separation
• Manganese
• Fluorescence

To prepare transparent 90GeO(2)-10BaO-0.1MnO glass-ceramics for Mn4+ red fluorescence, a glass was prepared by a melt-quenching method, and then the glass was crystallized at 700 and 800 degrees C for various seconds. The crystallization processes were investigated by measuring and observing the glass-ceramics using an XRD analyzer, an IR absorption spectrophotometer, a field emission scanning electron microscope, and a fluorescence spectrometer. As a result, for the heat treatment at 700 degrees C, alpha-GeO2 and BaGe4O9 crystals doped with Mn4+ ions were formed with oxidation of Mn2+ ions to Mn4+ ones in the surface layer by heterogeneous nucleation. For the heat treatment at 800 degrees C, by homogeneous crystallization with nano-sized phase separation, alpha-GeO2 and Mn4+:-BaGe4O9 nanocrystals were formed in a GeO2-rich phase and an Mn4+ ions-containing BaO-rich phase, respectively. In this study, transparent 90GeO(2)-10BaO-0.1MnO glass-ceramics crystallized at 800 degrees C for 10(2.0) s by homogeneous crystallization with nano-sized phase separation, showed the strongest red fluorescence band due to the E-2((2)G) -> (4)A(2) (F-4) transition of Me4+ ions in the BaGe4O9 nanocrystals.

• 出版日期2015-6-15