Magnetic properties of a quasi-two-dimensional S = 1/2 Heisenberg antiferromagnet with distorted square lattice
Magnetic properties of a quasi-two-dimensional S = 1/2 Heisenberg antiferromagnet with distorted square lattice
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具有扭曲方晶格的准二维 S = 1/2 海森堡反铁磁体的磁特性
DOI：
10.1103/physrevb.95.235135
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
and Masayuki Hagiwara
中科院分区：
文献类型：
--
作者：
Hironori Yamaguchi;Yusuke Tamekuni;Yoshiki Iwasaki;Rei Otsuka;Yuko Hosokoshi;Takanori Kida;and Masayuki Hagiwara
我们成功地合成了Verdazyl自由基-V的单晶。从头算分子轨道计算表明，两个主要的反铁磁相互作用，和，形成一个扭曲的正方形晶格。我们用量子Monte Carlo方法解释了基于正方晶格海森堡反铁磁体的磁性，并考察了晶格畸变和面间相互作用对磁性的影响.在低于6.4 K的低温区域，我们观察到各向异性的磁行为伴随着相变的磁有序状态。电子自旋共振信号在共振场和线宽的温度依赖性方面表现出各向异性行为。我们解释的频率依赖性的共振场在有序的相位使用平均场近似与平面外的易轴各向异性，这会导致自旋翻转相变在约0.4 T的场垂直于平面。此外，各向异性偶极场提供关于易轴各向异性的存在的支持信息。这些结果表明，该模型的晶格畸变、各向异性和面间相互作用足够小，不影响正方晶格Heisenberg反铁磁体的本征行为.
We successfully synthesize single crystals of the verdazyl radical-V.Ab initiomolecular orbital calculations indicate that the two dominant antiferromagnetic interactions,and, form andistorted square lattice. We explain the magnetic properties based on thesquare lattice Heisenberg antiferromagnet using the quantum Monte Carlo method, and examine the effects of the lattice distortion and the interplane interaction contribution. In the low-temperature regions below 6.4 K, we observe anisotropic magnetic behavior accompanied by a phase transition to a magnetically ordered state. The electron spin resonance signals exhibit anisotropic behavior in the temperature dependence of the resonance field and the linewidth. We explain the frequency dependence of the resonance fields in the ordered phase using a mean-field approximation with out-of-plane easy-axis anisotropy, which causes a spin-flop phase transition at approximately 0.4 T for the field perpendicular to the plane. Furthermore, the anisotropic dipole field provides supporting information regarding the presence of the easy-axis anisotropy. These results demonstrate that the lattice distortion, anisotropy, and interplane interaction of this model are sufficiently small that they do not affect the intrinsic behavior of thesquare lattice Heisenberg antiferromagnet.