Oxygen exchange and diffusion measurements: The importance of extracting the correct initial and boundary conditions
Oxygen exchange and diffusion measurements: The importance of extracting the correct initial and boundary conditions
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DOI：
10.1016/j.ssi.2005.05.010
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发表时间：
2005-07-01
影响因子：
3.2
通讯作者：
Chater, RJ
中科院分区：
文献类型：
--
作者：
De Souza, RA;Chater, RJ
O-18/O-16交换后的二次离子质谱（西姆斯）分析通常用于确定氧化物材料的氧示踪剂扩散系数D* 和氧表面交换系数k*。传统上，该实验包括在恒定同位素分数c（g）的气体体积中退火平衡的半无限介质，其中初始同位素分数为c（bg）。在本文中，我们考虑的错误，可能会被引入到传输参数，如果传统的初始和边界条件的假设，当提取D* 和k* 从实验数据，但实际条件下，进行退火，是显着不同的。特别注意的是从气相中的同位素耗尽的问题时，退火材料，显示高值的D* 和k*。(c)2005 Elsevier B. V.保留所有权利。
O-18/O-16 exchange followed by Secondary Ion Mass Spectrometry (SIMS) analysis is often used to determine the oxygen tracer diffusion coefficient D* and the oxygen surface exchange coefficient k* of oxide materials. Conventionally, the experiment consists of annealing an equilibrated, semi-infinite medium, in which the initial isotope fraction is c(bg), in a volume of gas of constant isotope fraction c(g). In this paper we consider the errors that may be introduced into the transport parameters if the conventional initial and boundary conditions are assumed, when extracting D* and k* from experimental data, but the actual conditions, under which the anneal was carried out, are significantly different. Particular attention is given to the problem of isotope depletion from the gas phase when annealing materials that display high values of D* and k*. (c) 2005 Elsevier B.V. All rights reserved.