Although nitrogen in the Earth’s interior has attracted significant attention recently, it remains the most enigmatic of the light elements in the Earth’s core. In this work, synchrotron X-ray diffraction (XRD) and electrical conductivity experiments were conducted on iron nitrides Fe₂N and Fe₄N in diamond anvil cells up to about 70 GPa at ambient temperature. These results show that iron nitrides are stable up to at least 70 GPa. From the equation of state (EOS) parameters, iron nitrides are more compressible than iron carbides. Moreover, using the van der Pauw method and Wiedemann-Franz law, the electrical and thermal conductivity of samples were determined to be much lower than that of iron carbides. The conductivities of Fe₂N and Fe₄N were similar at 20–70 GPa, suggesting no evident effects by varying the N stoichiometries in iron nitrides. Iron nitrides are less dense and conductive but more compressible than carbides at 0–70 GPa. This study indicates that less nitrogen than carbon can explain geophysical phenomena in the deep Earth, such as the density deficit.

尽管近来地球内部的氮已引起广泛关注，但它仍然是地球核心中最神秘的轻元素。在这项工作中，在环境温度下对高达70 GPa的金刚石砧座中的氮化铁Fe ₂ N和Fe ₄ N进行了同步加速器X射线衍射（XRD）和电导率实验。这些结果表明氮化铁在至少70 GPa的范围内是稳定的。根据状态方程（EOS）参数，氮化铁比碳化铁更易压缩。此外，使用范德堡方法和维德曼-弗朗兹定律，确定样品的电导率和导热率远低于碳化铁。Fe ₂ N和Fe ₄的电导率N在20–70 GPa时相似，表明通过改变氮化铁中N的化学计量没有明显的影响。氮化铁的密度和导电性较弱，但在0-70 GPa时比碳化物更易压缩。这项研究表明，氮比碳少可以解释地球深处的地球物理现象，例如密度不足。