With the goal of answering the highly debated question of whether the presence of Ni at the Earth’s inner core can make body-centered cubic (bcc) Fe stable, we performed a computational study based on first-principles calculations on bcc, hexagonal closed packed (hcp), and face-centered cubic (fcc) structures of the Fe_1−xNi_x alloys (x = 0, 0.0312, 0.042, 0.0625, 0.084, 0.125, 0.14, 0.175) at 200–364 GPa and investigated their relative stability. Our thorough study reveals that the stability of Ni-doped bcc Fe is crucially dependent on the nature of the distribution of Ni in the Fe matrix. We confirm this observation by considering several possible configurations for a given concentration of Ni doping. Our theoretical evidence suggests that Ni-doped bcc Fe could be a stable phase at the Earth’s inner core condition as compared to its hcp and fcc counterparts.

中文翻译：

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镍掺杂：使体心立方铁稳定在地球内核的可行途径

为了回答备受争议的问题，即地球内核处Ni的存在是否可以使体心立方（bcc）Fe稳定，我们基于对bcc，六方密堆积（bcc）的第一性原理计算进行了计算研究（ hcp）和Fe _{1- x} Ni _x合金（x= 200、364 GPa时分别为0、0.0312、0.042、0.0625、0.084、0.125、0.14、0.175），并研究了它们的相对稳定性。我们的深入研究表明，掺Ni的bcc Fe的稳定性关键取决于Ni在Fe基体中的分布性质。我们通过考虑给定浓度的Ni掺杂的几种可能的构型来确认这一观察结果。我们的理论证据表明，与hcp和fcc对应物相比，掺Ni的bcc Fe在地球的内核条件下可能是稳定相。