Oxygen diffusion in sanidine feldspar and a critical appraisal of oxygen isotope-mass-effect measurements in non-cubic materials
Oxygen diffusion in sanidine feldspar and a critical appraisal of oxygen isotope-mass-effect measurements in non-cubic materials
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透长石中的氧扩散以及非立方材料中氧同位素质量效应测量的严格评估
DOI：
10.1080/01418619708205154
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发表时间：
1997
影响因子：
1.6
通讯作者：
J. Göttlicher
中科院分区：
文献类型：
--
作者：
R. Freer;K. Wright;H. Kroll;J. Göttlicher
在温度550-850 ℃、总压1 kbar的条件下，进行了透长石单晶与富17 O和富18 O水之间的氧交换实验。用离子探针测定了氧同位素在垂直于（001）方向上的扩散分布。两种同位素的扩散数据都遵循单一的阿耳忒弥斯关系式：D = 3·95 × 10−12 exp（−109·7 ± 4kJ mol−1/RT）m2 s −1。将每个剖面的17 O和18 O浓度-距离数据以双“反误差函数图”的形式同时结合起来，可以直接获得扩散系数的比值D17/D18，并估算同位素质量效应E α β。在550 ° C和650°C下，E α β值在0.83 - 1.03之间，表明透长石中氧扩散的间隙机制，尽管不确定度（± 0.10）并不排除空位机制。建立了同位素质量效应的计算方法和数学分析。
Abstract Oxygen exchange experiments have been performed between single crystals of sanidine feldspar and water enriched in 17O and 18O; temperatures were in the range 550–850°C and total pressure 1 kbar. Oxygen isotope diffusion profiles in a direction perpendicular to (001) were determined with an ion microprobe. The diffusion data for both isotopes followed a single Arrhenius relationship described by D = 3·95 × 10−12 exp(−109·7 ± 4kJ mol−1/RT)m2s−1. Combining concentration-distance data for 17O and 18O simultaneously for each profile in the form of a double ‘inverse error function plot’ enabled the ratio D 17/D 18 of diffusion coefficients to be obtained directly, and the isotope mass effect E α β to be estimated. At 550 and 650°C E α β values were in the range 0·83–1·03, suggesting an interstitial mechanism for oxygen diffusion in sanidine feldspar, although the uncertainties (±0·10) do not preclude a vacancy mechanism. A methodology and mathematical analysis has been developed for isotope-mass-effec...