Self-diffusion of lithium in LiAlSi2O6 glasses studied using mass spectrometry.
Self-diffusion of lithium in LiAlSi2O6 glasses studied using mass spectrometry.
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DOI：
10.1021/jp209319b
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发表时间：
2012-01
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影响因子：
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通讯作者：
A. Welsch;Harald Behrens;Ingo Horn;S. Ross;P. Heitjans
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文献类型：
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作者：
A. Welsch;Harald Behrens;Ingo Horn;S. Ross;P. Heitjans
为了提高我们对锂在玻璃中的输运机制的理解，我们对锂辉石组成(LiAlSi（2)O(6)）玻璃进行了扩散和离子电导率研究。在扩散偶实验中，在482 ~ 732 K的温度下，对具有不同锂同位素（天然锂和纯(7)锂）的化学性质相同的玻璃进行处理。采用飞秒紫外激光烧蚀结合电感耦合等离子体质谱法（LA ICP-MS）对扩散后的锂同位素谱进行了测量。通过拟合同位素谱，确定了锂在玻璃中的自扩散系数。在一些扩散实验中，用阻抗谱法间歇地测量了样品的电导率。结合离子电导率和自扩散率可以得到一个温度无关的相关因子~0.50，这表明Li离子的运动在这种类型的玻璃中具有很强的相关性。LiAlSi(2)O(6)玻璃中的锂自扩散率与硅酸锂玻璃中的锂自扩散率非常相似，尽管拉曼光谱显示了这些玻璃之间的结构差异；也就是说，硅酸铝完全聚合，而硅酸锂玻璃含有大量的非桥氧。
In order to improve our understanding of the transport mechanisms of lithium in glasses, we have performed diffusion and ionic conductivity studies on spodumene composition (LiAlSi(2)O(6)) glasses. In diffusion couple experiments pairs of chemically identical glasses with different lithium isotopy (natural Li vs pure (7)Li) were processed at temperatures between 482 and 732 K. Profiles of lithium isotopes were measured after the diffusion runs innovatively applying femtosecond UV laser ablation combined with inductively coupled plasma mass spectrometry (LA ICP-MS). Self-diffusion coefficients of lithium in the glasses were determined by fitting the isotope profiles. During some of the diffusion experiments the electrical conductivity of the samples was intermittently measured by impedance spectrometry. Combining ionic conductivity and self-diffusivity yields a temperature-independent correlation factor of ~0.50, indicating that motions of Li ions are strongly correlated in this type of glasses. Lithium self-diffusivity in LiAlSi(2)O(6) glass was found to be very similar to that in lithium silicate glasses although Raman spectroscopy demonstrates structural differences between these glasses; that is, the aluminosilicate is completely polymerized while the lithium silicate glasses contain large fractions of nonbridging oxygen.