Abstract—Phase transitions in the antiferromagnetic Heisenberg model on the body-centered cubic lattice were studied using the replica algorithm of the Monte Carlo method, taking into account the interactions between the first and second neighbors. The investigations were performed for the ratio of the value of the exchange interactions between the nearest and second neighbors in the range 0.0 ≤ r ≤ 1.0. The phase diagram of critical temperature versus the value of interaction between the second neighbors was constructed. The region in the diagram where the transition from antiferromagnetic to paramagnetic phase is of the first order was discovered for the first time in this study.

摘要—使用蒙特卡罗方法的复制算法，考虑了第一和第二邻居之间的相互作用，研究了以体心为中心的立方晶格上的反铁磁Heisenberg模型中的相变。该调查是对最近和第二邻居之间的交换相互作用的值的范围为0.0≤的比率进行ř ≤1.0。构造了临界温度与第二个邻域之间相互作用值的相图。在该研究中，首次发现了图中从反铁磁相到顺磁相的跃迁为一阶的区域。