Sodium-potassium interdiffusion in potassium-rich alkali feldspar II: Composition- and temperature-dependence obtained from cation exchange experiments
Sodium-potassium interdiffusion in potassium-rich alkali feldspar II: Composition- and temperature-dependence obtained from cation exchange experiments
复制标题
富钾碱长石 II 中的钠钾相互扩散：从阳离子交换实验中获得的成分和温度依赖性
DOI：
10.2475/09.2014.03
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发表时间：
2014
影响因子：
2.9
通讯作者：
G. Giester
中科院分区：
文献类型：
--
作者：
A. Schäffer;E. Petrishcheva;G. Habler;R. Abart;D. Rhede;G. Giester
在800℃~1000℃、近常压条件下，利用Eifel中宝石级闪锌矿与碱卤化物熔体之间的阳离子交换，实验研究了Na-K在无序富钾碱性长石中的互扩散。测定了钾摩尔分数在0.65≤XOR≤0.99范围内的钠-钾互扩散系数DNaK。在0.65≤异或≤为0.95时，钠-钾互扩散系数基本上与组成无关。在异或≥为0.95时，随钾摩尔分数的增加而急剧上升。垂直于(001)的扩散比垂直于(010)的扩散快约一个数量级，且对温度的依赖性较小。对描述钠钾互扩散系数DNaK=D0Exp(−Ea/RT)与温度依赖关系的Arrhenius方程的参数进行了估算，并用相应的钠钾示踪扩散系数将直接测定的结果与理论计算结果进行了比较，并讨论了观测到的钠钾互扩散随组成和温度变化的过程。
Na-K interdiffusion in disordered potassium-rich alkali feldspar was studied experimentally using cation exchange between gem quality sanidine from the Eifel and alkali-halide melt at temperatures of 800 °C to 1000 °C and at close to ambient pressure. Sodium-potassium interdiffusion coefficient DNaK was determined for potassium mole fractions in the range 0.65 ≤ XOr ≤ 0.99. At 0.65 ≤ XOr ≤ 0.95 the sodium-potassium interdiffusion coefficient is largely independent of composition. At XOr ≥ 0.95, it rises sharply with increasing potassium mole fraction. Diffusion perpendicular to (001) is about one order of magnitude faster and less strongly temperature dependent than perpendicular to (010). The parameters of the Arrhenius equation describing the temperature dependence of the sodium-potassium interdiffusion coefficient DNaK = D0Exp (−EA/RT) were estimated as The results of our direct determinations are compared with theoretical calculations using the corresponding sodium- and potassium tracer-diffusion coefficients, and the processes underlying the observed composition- and temperature dependence of sodium-potassium interdiffusion are discussed.
影响因子：
9.4
作者：
Britton, T. Benjamin;Wilkinson, Angus J.
通讯作者：
Wilkinson, Angus J.