Theory of melting: thermodynamic basis of Lindemann's law
Theory of melting: thermodynamic basis of Lindemann's law
复制标题
熔化理论：林德曼定律的热力学基础
DOI：
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发表时间：
1977
期刊：
影响因子：
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通讯作者：
R. Irvine
中科院分区：
文献类型：
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作者：
F. Stacey;R. Irvine
一个熔融方程密切类似的林德曼的熔融定律的微分形式，其中涉及的熔点的压力方面的热Griineisen参数和不可压缩性，来自克劳修斯-克拉珀龙关系的假设，MieGriineisen方程可以直接适应描述的压力变化与熔化在恒定体积。这一假设意味着熔化只是晶体结构的一个微小扰动，因此原子配位几乎不受影响，原子键只是被拉伸或压缩。看来，“正常”熔化符合这一假设合理密切，但偏离林德曼定律发生时，材料在熔化过程中发生重大变化的协调。林德曼定律的一个特别的优点是，它允许将熔点外推到地球内部深处的压力。外推的铁硫共晶的数据表明，在地球的内部（固体）和外部（液体）核心的边界温度为4160 K。绝热外推到核幔边界给出2940 K的地幔底部。
A melting equation closely resembling the differential form of Lindemann's melting law, which relates the melting point to the pressure in terms of the thermal Griineisen parameter and incompressibility, is derived from the Clausius-Clapeyron relation with the assumption that the MieGriineisen equation can be adapted directly to describe the pressure change associated with melting at constant volume. This assumption implies that melting is only a minor perturbation of the crystal structure, such that the atomic coordination is almost unaffected and that atomic bonds are merely stretched or compressed. It appears that 'normal' melting complies with this assumption reasonably closely but that departures from Lindemann's law occur when materials undergo major changes in coordination during melting. A particular merit of Lindemann's law is that it allows the extrapolation of melting points to the pressures of the Earth's deep interior. Extrapolation of data on the ironsulphur eutectic suggests a temperature of 4160 K at the boundary of the Earth's inner (solid) and outer (liquid) cores. Adiabatic extrapolation to the core-mantle boundary gives 2940 K at the base of the mantle.