Theory of impurity diffusion in metals
Theory of impurity diffusion in metals
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金属中的杂质扩散理论
DOI：
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发表时间：
1964
期刊：
影响因子：
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通讯作者：
A. Claire
中科院分区：
文献类型：
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作者：
A. Claire
LeClaire在1962年的一篇论文中提出了一个简单的静电模型，用来计算杂质在金属中扩散激活能与纯金属中自扩散激活能之差ΔQ。在本文中，该模型被扩展到处理具有相同的化合价作为溶剂（同价杂质）的杂质的扩散。在这种情况下，杂质由深度等于溶质和溶剂的电子基态能量之差的方势阱表示。由这种“杂质”引起的微扰势的值，在M-Fermi近似和March和Murray方程的一阶解中计算，用于计算ΔQ。对于所有目前已知的同价扩散情况，计算给出的ΔQ值接近于观察到的值，并且符号总是正确的。
Abstract In a previous paper (Le Claire 1962) a simple electrostatic model was proposed for calculating the difference ΔQ between the activation energy for diffusion of an impurity in a metal and that for self-diffusion in the pure metal. The model is extended in the present paper to deal with the diffusion of impurities having the same valency as the solvent (homovalent impurities). For such cases the impurity is represented by a square potential well of depth equal to the difference between the electron-ground state energies of solute and solvent. Values of the perturbation potential due to such an ‘impurity’, calculated in both a Thomas-Fermi approximation and from a first-order solution of the March and Murray equations, are used to calculate ΔQ. For all presently known cases of homovalent diffusion the calculations give values for ΔQ close to those observed and always of the correct sign.