【摘要】 根据Grüneisen物态方程、Hugoniot内能守恒方程和最新发表的铁的热物理参数,计算了-ε(hcp)铁和液态铁的理论Hugoniot曲线。计算的Hugoniot曲线与最新修正的铁的实验数据[J Appl Phys,2000,88:5496]在总体上符合很好,并且可以细分为两个部分:在约低于200 GPa的压强区,用ε-铁模型的计算结果与实验结果符合很好;在约高于260 GPa的压强区,用液态铁模型的计算结果与实验数据也符合得比较好;对介于200~260 GPa之间的压强区,则归属于由ε-铁向液态铁转变的混合相区。这意味着铁的Hugoniot曲线在约200 GPa处出现的微小偏折是由固-液相变引起的,从而否定了Brown[Geophy Res Lett,2001,28:4339]提出的它是一次由ε-铁向另一个未知结构的某个固相铁的相转变的见解。更多还原

【Abstract】 A theoretical Hugoniot curve of iron has been calculated based on Grüneisen equation of state and internal energy conservation consideration,using a set of optimized or thermophysical parameters and both ε-and liquid-iron models.This determined Hugoniot curve is well in accord with the revised Hugoniot data [J Appl Phys,2000,88:5496] on the whole,and could be further divided into two parts.The first one can well describe the revised data below ~200 GPa with ε-phase model,while the second can approximately replicate the revised data above ~260 GPa with liquid-phase model.It is thus convinced that the range between ~200 GPa and ~260 GPa should be in solid/liquid mixed state,i.e,a small kink appearing on the revised Hugoniot at ~200 GPa is due to a solid-liquid transition,rather than a solid-solid transition at ~200 GPa that was inferred from Brown’s analysis [Geophys Res Lett,2001,28:4339].更多还原