论文标题
立方双钙钛矿Ba2niiro6中的磁挫败感6
Magnetic frustration in the cubic double perovskite Ba2NiIrO6
论文作者
论文摘要
混合过渡金属氧化物由于其多个自由度（例如$，晶格，电荷，自旋和轨道）和多功能性能而继续引起人们的注意。在这里，我们使用晶体场理论，superexchange模型分析，密度功能计算和平行回火蒙特卡洛（PTMC）模拟，研究了新合成的双钙钛矿Ba $ _2 $ _6 $的磁性和电子特性。我们的结果表明，ba $ _2 $ niiro $ _6 $具有ni $^{2+} $（$ t_ {2g}^{6} e_ {g}^{2}^{2} $） - ir $^{6+} $（6+} $（$ t_ {2g}^{2G}^{2G}^{3} $）。第一个最近的邻居（1NN）Ni $^{2+} $ - IR $^{6+} $ ions更喜欢Ferromagnetic（FM）耦合，如Goodenough-Kanamori-Anderson规则所期望的，这与实验性的反铁磁性（AF）相矛盾（Af）ba $ _____________________________________________________6 $ niiro $ niiro。我们发现，强大的2NN AF耦合在FCC的sublattices中感到沮丧，并且在确定观察到的AF基态方面起着重要作用。我们还证明，$ j _ {\ rm eff} $ = 3/2和$ j _ {\ rm eff} $ = 1/2个状态由旋转 - 轨道耦合引起的状态，这将在低维（例如分层）宝元中表现出来，但是对于立方体ba $ $ _2 $ niiro ba ba $ niiro ba ba $ niire ba ba ba $ niiro ba ba ba ba $ niiro。我们的PTMC模拟表明，当包括远距离（2NN和3NN）AF相互作用时，将获得具有$ t _ {\ rm n} $ = 66 k的AF过渡，它与实验性51 k可以相媲美。对的是，我们建议使用2 $ 2 $ \ times $ 2 $ \ times $ 2 $ 2 $ 2 $ 2 $ ni $ 2 $ ni $ ni $ ni $ ni $ ni $ ni $ ni。
Hybrid transition metal oxides continue to attract attention due to their multiple degrees of freedom ($e.g.$, lattice, charge, spin, and orbital) and versatile properties. Here we investigate the magnetic and electronic properties of the newly synthesized double perovskite Ba$_2$NiIrO$_6$, using crystal field theory, superexchange model analysis, density functional calculations, and parallel tempering Monte Carlo (PTMC) simulations. Our results indicate that Ba$_2$NiIrO$_6$ has the Ni$^{2+}$ ($t_{2g}^{6}e_{g}^{2}$)-Ir$^{6+}$ ($t_{2g}^{3}$) charge states. The first nearest-neighboring (1NN) Ni$^{2+}$-Ir$^{6+}$ ions prefer a ferromagnetic (FM) coupling as expected from the Goodenough-Kanamori-Anderson rules, which contradicts the experimental antiferromagnetic (AF) order in Ba$_2$NiIrO$_6$. We find that the strong 2NN AF couplings are frustrated in the fcc sublattices, and they play a major role in determining the observed AF ground state. We also prove that the $J_{\rm eff}$ = 3/2 and $J_{\rm eff}$ = 1/2 states induced by spin-orbit coupling, which would be manifested in low-dimensional (e.g., layered) iridates, are however not the case for cubic Ba$_2$NiIrO$_6$. Our PTMC simulations show that when the long-range (2NN and 3NN) AF interactions are included, an AF transition with $T_{\rm N}$ = 66 K would be obtained and it is well comparable with the experimental 51 K. Meanwhile, we propose a possible 2$\times$2$\times$2 noncollinear AF structure for Ba$_2$NiIrO$_6$.
