The influence of external pressures on the structural and magnetic properties of the FeNi alloy is elucidated using density functional theory (DFT) and Monte Carlo simulation. Utilizing a range of pressures, the study showcases compressive behavior in lattice constants, with both a and c exhibiting reductions. A sharp decline in magnetic moments is recorded at a critical pressure of 54 GPa. Indicating a magnetic phase transition from ferro to paramagnetic phase. Beyond this critical pressure, dynamical instability becomes evident, attributable to the aforementioned magnetic phase transition. Further examination of exchange interaction parameters reveals that while Fe–Fe interactions exhibited a consistent decrease with pressure, the FeNi and NiNi interactions remained relatively stable across the examined pressure range. At pressures close to 0 GPa, the Curie temperature ($T_C$) was found to be around 838 K. As the external pressure is applied, a consequential decline in $T_C$ is witnessed, suggesting a significant sensitivity of the magnetic phase transition to external pressures. In particular, this study indicates that the FeNi alloy is sensitive to external pressures, emphasizing some relation between structural and magnetic properties.

利用密度泛函理论（DFT）和蒙特卡罗模拟阐明了外部压力对 FeNi 合金结构和磁性能的影响。利用一系列压力，该研究展示了晶格常数的压缩行为，其中a和c都表现出减小。在 54 GPa 的临界压力下记录到磁矩急剧下降。表示从铁相到顺磁相的磁相变。超过这个临界压力，由于上述磁相变，动态不稳定性变得明显。对交换相互作用参数的进一步检查表明，虽然 Fe-Fe 相互作用表现出随压力一致下降的趋势，但 FeNi 和 NiNi 相互作用在所检查的压力范围内保持相对稳定。在压力接近 0 GPa 时，居里温度 (${\mathrm{时间}}_C$）被发现约为 838 K。当施加外部压力时，随之而来的下降${\mathrm{时间}}_C$见证了磁相变对外部压力的显着敏感性。特别是，这项研究表明 FeNi 合金对外部压力敏感，强调了结构和磁性能之间的某些关系。