论文标题
nd $ _x $ fe $ _ {1-x} $无定形合金的交换耦合常数的第一原理研究
First-principles study of exchange coupling constants in Nd$_x$Fe$_{1-x}$ amorphous alloy
论文作者
论文摘要
我们调查了ND $ _x $ _x $ _x $ fe $ _ {1-x} $无晶体合金的交换耦合常数$ j_ {ij} $在第一原则计算的框架内具有不同的成分。我们观察到$ j_ {ij} $的强大原子依赖性及其波动。我们表明该构图强烈影响$ j_ {ij} $的距离依赖性。计算出的居里温度的组成依赖性对于$ x <0.5 $来说是适中的。为了检查局部环境对交换耦合的影响，我们使用Gabriel图展示了对协调结构和交换耦合常数的联合分析。我们的研究表明，居里温度主要由平均的$ j_ {ij} $和由相邻原子对确定的配位数所主导。我们还观察到，随着周围ND原子的数量增加，Fe-fe和Fe-之间的交换耦合变得更强大。
We investigate the exchange coupling constant $J_{ij}$ in Nd$_x$Fe$_{1-x}$ amorphous alloys with different compositions within the framework of first-principles calculation. We observed a strong atomic-dependence of $J_{ij}$ and its fluctuations. We show that the composition strongly affects the distance dependence of $J_{ij}$. Composition dependence of calculated Curie temperatures is modest for $x<0.5$. To examine the effect of the local environment on the exchange couplings, we demonstrate combined analyses of the coordination structure and exchange coupling constants using the Gabriel graph. Our study reveals that the Curie temperatures are mostly dominated by the averaged $J_{ij}$ and coordination numbers determined by the pairs of neighboring atoms. We also observed that the exchange couplings between Fe--Fe and Fe--Nd become stronger with increasing the number of surrounding Nd atoms.
