论文标题
非常孤立的2D旋转-1/2 $抗铁磁的海森伯格层，在基于分子的磁铁杯中与小型交换耦合
Extremely well isolated 2D spin-$1/2$ antiferromagnetic Heisenberg layers with small exchange coupling in the molecular-based magnet CuPOF
论文作者
论文摘要
我们报告了新合成的Cu $^{2+} $的全面表征 - 基于分子磁铁[Cu（pz）$ _ 2 $（2-hopy）$ _ 2 $]（pf $ _6 $）$ _ 2 $（cupof） c $ _5 $ h $ _4 $ nho。从理论模型的比较到散装磁力测定，特定热量，$μ^+$ sr，ESR，ESR和NMR光谱的比较，该材料被确定为2D式静态$ s = 1/2 $ s = 1/2 $ andigner-negrane-neign-neger-neger-keplm j/k k k y k k y k y k y k y k y y y y y y y $ j keyppling of j/ 6.80（5）$ K，并且非常小的层间相互作用约为1 mk。在零字段，块状磁力测定法揭示了由弱固有的易于平面各向异性的存在引起的自旋相关性从各向同性到$ xy $类型的旋转相关性的交叉。在层间耦合的影响下，由低温$ xy $各向异性驱动的远程顺序的过渡发生在$ t_ \ mathrm {n} = 1.38（2）$ k，如$μ^+$ sr所示。在应用的磁场中，我们的$^1 $ H-NMR数据显示了磁各向异性的强烈增加，这表现为在$ t_ \ mathrm {n} = 2.8 $ k和7 t下的过渡温度的明显增强以相称的长距离顺序。
We report on a comprehensive characterization of the newly synthesized Cu$^{2+}$-based molecular magnet [Cu(pz)$_2$(2-HOpy)$_2$](PF$_6$)$_2$ (CuPOF), where pz = C$_4$H$_4$N$_2$ and 2-HOpy = C$_5$H$_4$NHO. From a comparison of theoretical modeling to results of bulk magnetometry, specific heat, $μ^+$SR, ESR, and NMR spectroscopy, this material is determined as an excellent realization of the 2D square-lattice $S=1/2$ antiferromagnetic Heisenberg model with a moderate intraplane nearest-neighbor exchange coupling of $J/k_\mathrm{B} = 6.80(5)$ K, and an extremely small interlayer interaction of about 1 mK. At zero field, the bulk magnetometry reveals a temperature-driven crossover of spin correlations from isotropic to $XY$ type, caused by the presence of a weak intrinsic easy-plane anisotropy. A transition to long-range order, driven by the low-temperature $XY$ anisotropy under the influence of the interlayer coupling, occurs at $T_\mathrm{N} = 1.38(2)$ K, as revealed by $μ^+$SR. In applied magnetic fields, our $^1$H-NMR data reveal a strong increase of the magnetic anisotropy, manifested by a pronounced enhancement of the transition temperature to commensurate long-range order at $T_\mathrm{N} =2.8$ K and 7 T.
