Field-induced XY and Ising ground states in a quasi-two-dimensional S=1/2 Heisenberg antiferromagnet
Field-induced XY and Ising ground states in a quasi-two-dimensional S=1/2 Heisenberg antiferromagnet
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DOI：
10.1103/physrevb.84.184402
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发表时间：
2011-11-04
影响因子：
3.7
通讯作者：
Manson, Jamie L.
中科院分区：
文献类型：
--
作者：
Kohama, Yoshimitsu;Jaime, Marcelo;Manson, Jamie L.
对准二维海森堡反铁磁体[Cu（pyz）（2）（pyO）（2）]（PF 6）（2）进行了高达35 T的高场比热（C-p）和磁化率（chi）测量。虽然没有观察到C-p异常下降到0.5 K在零磁场，平行于晶体学的ab-平面的应用领域诱导的C-p的一个类似于Pendida的异常，这表明伊辛型磁序。另一方面，当磁场平行于c轴时，C-p和chi显示出XY型反铁磁性的证据。这种依赖于场取向的发生是因为极端的二维性允许本征（零场）自旋各向异性主导层间耦合，这迄今为止在其他材料中掩盖了这种效应。
High field specific heat up to 35 T, C-p, and magnetic susceptibility, chi, measurements were performed on the quasi-two-dimensional (2D) Heisenberg antiferromagnet [Cu(pyz)(2)(pyO)(2)](PF6)(2). While no C-p anomaly is observed down to 0.5 K in zero magnetic field, the application of field parallel to the crystallographic ab-plane induces a lambda-like anomaly in C-p, suggesting Ising-type magnetic order. On the other hand when the field is parallel to the c-axis, C-p and chi show evidence of XY-type antiferromagnetism. This dependence upon the field orientation occurs because the extreme two-dimensionality allows the intrinsic (zero field) spin anisotropy to dominate the interlayer coupling, which has hitherto masked such effects in other materials.