论文标题
化学障碍对L1 $ _0 $ -FENI（四岩）中磁交换相互作用的影响
Impact of chemical disorder on magnetic exchange interactions in L1$_0$-FeNi (tetrataenite)
论文作者
论文摘要
我们研究了使用基于第一原则的计算，研究化学障碍对L1 $ _0 $订购的FENI中的磁性交换耦合的影响（$ t _ {\ text {c}} $）。我们使用超级细胞对化学障碍进行建模，以说明各个原子周围特定的对称性局部化学环境。我们发现，对于不同的不相等的Fe-Fe对，最优势的最优势的邻居FE-FE相互作用的变化非常强，范围从约5 MeV到37 MeV，而在有序状态下的耦合强度为27 MeV。为了估计磁耦合常数的这种强烈变化对无序或部分有序状态的库丽温度的影响，我们研究了一个简单的海森贝格模型，在FCC晶格上具有随机的高斯二分发给最近的邻居耦合。我们针对此模型的蒙特卡洛模拟表明，相对于仅使用平均耦合的$ t _ {\ text {c}} $，$ t _ {\ text {c}} $的强烈变化的交换耦合可能会导致$ t _ {\ text {c}} $减少约10％。
We investigate the effect of chemical disorder on the magnetic exchange couplings and the Curie temperature ($T_{\text{c}}$) in L1$_0$-ordered FeNi using first-principles-based calculations. We use supercells to model chemical disorder, to account for the specific symmetry-broken local chemical environments around the individual atoms. We find a very strong variation of the most dominant first-nearest neighbor Fe-Fe interaction for different inequivalent Fe-Fe pairs, ranging from around 5 meV to 37 meV, compared to a coupling strength of 27 meV in the ordered state. To estimate the influence of such strong variations of the magnetic coupling constants on the Curie temperature of the disordered or partially ordered state, we study a simple Heisenberg model with random Gaussian-distributed nearest neighbor couplings on an fcc lattice. Our Monte Carlo simulations for this model indicate that strongly varying exchange couplings, such as those obtained for FeNi, can lead to a reduction of $T_{\text{c}}$ of around 10% relative to the one obtained using only the average coupling.
