Structural investigations of borosilicate glasses containing MoO3 by MAS NMR and Raman spectroscopies
Structural investigations of borosilicate glasses containing MoO3 by MAS NMR and Raman spectroscopies
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DOI：
10.1016/j.jnucmat.2009.10.059
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发表时间：
2010-01-01
影响因子：
3.1
通讯作者：
Neuville, D.
中科院分区：
文献类型：
--
作者：
Caurant, D.;Majerus, O.;Neuville, D.
玻璃组合物中的高钼浓度可能在熔体冷却过程中导致碱金属和碱土钼酸盐结晶，特别是在制备高放射性核玻璃废物形式时必须加以控制。为了了解钼添加对简化核玻璃结构的影响以及组分变化对钼酸盐结晶倾向的影响，通过增加MoO3或B2O3浓度，采用Si-29、B-11、Na-23 MAS NMR和拉曼光谱研究了属于sio2 -B2O3- na20 - cao -MoO3体系的两个系列玻璃的结构。MoO3用量的增加导致了硅酸盐网状结构的增加，但对BO4-单位的比例和Na+阳离子在玻璃结构中的分布没有显著影响。随着B2O3浓度的增加，观察到Na+阳离子分布的强烈演变，这可以解释熔体冷却过程中形成的钼酸盐晶体（CaMoO4或Na2MoO4）性质的演变。(C) 2009 Elsevier B.V.版权所有
High molybdenum concentration in glass compositions may lead to alkali and alkaline-earth molybdates crystallization during melt cooling that must be controlled particularly during the preparation of highly radioactive nuclear glassy waste forms. To understand the effect of molybdenum addition on the structure of a simplified nuclear glass and to know how composition changes can affect molybdates crystallization tendency, the structure of two glass series belonging to the SiO2-B2O3-Na2O-CaO-MoO3 system was studied by Si-29, B-11, Na-23 MAS NMR and Raman spectroscopies by increasing MoO3 or B2O3 concentrations. Increasing MoO3 amount induced an increase of the silicate network reticulation but no significant effect was observed on the proportion of BO4- units and on the distribution of Na+ cations in glass structure. By increasing B2O3 concentration, a strong evolution of the distribution of Na+ cations was observed that could explain the evolution of the nature of molybdate crystals (CaMoO4 or Na2MoO4) formed during melt cooling. (C) 2009 Elsevier B.V. All rights reserved.