论文标题
尖晶石结构化$ AB_2O_4 $化合物的异国多性性能：蒙特卡洛研究
Exotic multiferroic properties of spinel structured $AB_2O_4$ compounds: A Monte Carlo Study
论文作者
论文摘要
尖晶石结构化合物，$ ab_2o_4 $，由于具有异国情调的多种性特性而变得很特别。在$ ACR_2O_4 $（$ a $ = $ co $，$ mn $，$ fe $）中，由于非校准磁性旋转顺序，已经在实验上观察到可切换极化。在本文中，我们使用Monte Carlo Simulation在本文中证明了这种磁性自旋顺序，磁滞，两极分化和所谓的磁补偿效果的显微镜起源。通过仔细选择交换互动，我们能够解释各种实验发现，例如磁化与温度（T）行为，锥形稳定性，独特的磁性顺序和独特的磁性和极化，在代表性化合物$ COCR_2O_4 $中，这是$ AB_2O_4 $ Spinel家族中最知名的多效化合物。我们还研究了$ fe $ -substitution在$ cocr_2o_4 $中的效果，并发作很少的异国情调现象，例如磁补偿和标志可逆交换偏见效应。使用模仿替代作用的有效相互作用来研究这些效果。该家族中的另外两种化合物，$ comn_2o_4 $和$ cofe_2o_4 $，在未观察到圆锥电磁顺序和极化的地方，因为因此提供了明显的对比度。这里所有计算均使用由自旋电流模型计算的极化完成。该模型具有一定的限制，并且在低温和低磁场方面非常有效。但是该模型尽管限制了，它仍可以很好地重现标志可逆的交换偏置和磁补偿，例如现象。
Spinel structured compounds, $AB_2O_4$, are special because of their exotic multiferroic properties. In $ACr_2O_4$ ($A$=$Co$, $Mn$,$Fe$), a switchable polarization has been observed experimentally due to a non-collinear magnetic spin order. In this article, we demonstrated the microscopic origin behind such magnetic spin order, hysteresis, polarisation and the so-called magnetic compensation effect in $ACr_2O_4$ ($A$=$Co$, $Mn$,$Fe$, $Ni$) using Monte Carlo simulation. With a careful choice of the exchange interaction, we were able to explain various experimental findings such as magnetization vs. temperature (T) behavior, conical stability, unique magnetic ordering and polarization in a representative compound $CoCr_2O_4$ which is the best known multiferroic compound in the $AB_2O_4$ spinel family. We have also studied the effect of $Fe$-substitution in $CoCr_2O_4$, with an onset of few exotic phenomena such as magnetic compensation and sign reversible exchange bias effect. These effects are investigated using an effective interactions mimicking the effect of substitution. Two other compounds in this family, $CoMn_2O_4$ and $CoFe_2O_4$, are also studied where no conical magnetic order and polarisation was observed, as hence provide a distinct contrast. Here all calculations are done using the polarisation calculated by the spin-current model. This model has certain limitation and it works quite good for low temperature and low magnetic field. But the model despite its limitation it can reproduce sign reversible exchange bias and magnetic compensation like phenomena quite well.
