论文标题
与时空变化的均匀随机外部磁场对ISIN Spin-1/2三层方形Ferrimagnet的补偿的影响
Effect of the Uniform Random External Magnetic Field with Spatio-temporal Variation on Compensation in Ising Spin-1/2 Trilayered Square Ferrimagnet
论文作者
论文摘要
三层旋转1/2 Ising铁磁体是有趣的补偿现象的有趣的薄系统。在这项工作中，对这种系统在正方形的bravais晶格上的磁和热力学响应进行了一项大都市蒙特卡洛研究，该系统由均匀的随机外部磁场驱动，并具有时空变化。在两种不同的配置中，表面层由A组成，中层由ABA型堆叠中的B原子组成，而在AAB型堆叠中，顶层和中层由A-Otoms组成，而底层则由B-Otoms组成。类似原子（A-A和B-B）之间的磁耦合是铁磁，而与原子（A-B）之间的磁耦合，它是抗磁磁性的。对于时间依赖的外部均匀随机场，平均值始终设置为零，并且标准偏差变化，直到自旋场能与系统的主要合作能相当为止。研究结果表明，观察到的补偿和临界点移动和稳态磁性行为在n-，l-，p-和Q-之间移动。类型的铁磁性行为，具体取决于外部均匀随机场的强度。在越过磁场的标准偏差有限阈值的特定选择之后，补偿现象甚至消失了。因此，在2D汉密尔顿参数空间中，没有补偿的铁磁相的岛出现在相位区域内。对于这两种配置，这些岛屿的区域甚至随着外部场的标准偏差的增加而增长，σ，遵守形式的缩放关系：$ f（σ，a（σ））=σ^{ - b} a（σ）
Trilayered spin-1/2 Ising ferrimagnets are interesting thin systems for compensation phenomenon. In this work, a Metropolis Monte Carlo study is performed on the magnetic and thermodynamic response of such a system on square Bravais lattice, driven by uniform random external magnetic field with spatio-temporal variations. In two distinct configurations, the surface layers are made up of A and the mid-layer is made up of B atoms in a ABA type stacking while in AAB type stacking, the top-layer and the mid-layer is made up of A-atoms while the bottom layer is made up of B-atoms. The magnetic coupling between the like atoms (A-A and B-B) is ferromagnetic while between the unlike atoms (A-B), it is antiferromagnetic. For the time-dependent external uniform random field, the mean is always set to zero and the standard deviation is varied until spin-field energy is comparable to the dominant cooperative energy of the system. The findings show that the observed compensation and critical points shift and steady-state magnetic behaviours shift between N-, L-, P- and Q- etc. type of ferrimagnetic behaviours, depending upon the strength of external uniform random field. The compensation phenomenon even vanishes after crossing a finite threshold of standard deviation of the magnetic field for particular choices of the other controlling parameters. Thus islands of ferrimagnetic phase without compensation appear within the phase area with compensation of field-free case, in the 2D Hamiltonian parameter space. For both the configurations, the areas of such islands even grow with increasing standard deviation of the external field, σ, obeying a scaling relation of the form: $f (σ, A(σ)) = σ^{-b} A(σ)$ with $b_{ABA} = 1.958 \pm 0.122$ and $b_{AAB} = 1.783 \pm 0.118$ .
