Self-diffusion in liquid Fe at high pressure
Self-diffusion in liquid Fe at high pressure
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DOI：
10.1016/s0031-9201(02)00011-0
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发表时间：
2002-04-29
影响因子：
2.3
通讯作者：
Dobson, DP
中科院分区：
文献类型：
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作者：
Dobson, DP
测定了铁液在1883 ~ 2393 K和2 ~ 20gpa范围内的自扩散率。在研究的压力范围内存在很大的压力依赖性，简单的阿伦尼乌斯外推到外核条件会产生不切实际的低扩散率。然而，所涵盖的大压力和温度范围允许使用实验结果测试不同的先验扩散模型。自由体积模型[J]。化学。物理学第31号（1959）[1164]与实验数据非常吻合，并为将结果外推到外核条件提供了基础。对4300 K时的地核-地幔边界（CMB）压力的外推得出，液态铁的自扩散系数为2.5 × 10(-5) cm(2) s(-1)，对应的黏度为11 mPa s，与之前的理论估计基本一致。(C) 2002 Elsevier Science B.V.版权所有
The self-diffusivity of liquid iron has been measured between 2 and 20 GPa and 1883 and 2393 K. There is a large pressure dependence across the pressure range studied and simple Arrhenius extrapolation to outer core conditions yields unrealistically low diffusivities, The large pressure and temperature range covered, however, allows different a priori diffusion models to be tested using the experimental results. The free volume model [J. Chem. Phys. 31 (1959) 1164] is found to be in excellent agreement with the experimental data and provides a basis for extrapolation of the results to outer core conditions. An extrapolation to core-mantle boundary (CMB) pressure at 4300 K yields a self-diffusivity for liquid iron of 2.5 x 10(-5) cm(2) s(-1), which corresponds to a viscosity of 11 mPa s, in reasonable agreement with previous, theoretical, estimates. (C) 2002 Elsevier Science B.V. All rights reserved.