Spin configuration in the 1/3 magnetization plateau of azurite determined by NMR.
Spin configuration in the 1/3 magnetization plateau of azurite determined by NMR.
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DOI：
10.1103/physrevlett.102.127205
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发表时间：
2009-01
影响因子：
8.6
通讯作者：
F. Aimo;S. Krämer;M. Klanjšek;M. Horvatić;C. Berthier;H. Kikuchi
中科院分区：
文献类型：
--
作者：
F. Aimo;S. Krämer;M. Klanjšek;M. Horvatić;C. Berthier;H. Kikuchi
利用高磁场（63,65）Cu核磁共振谱测定了蓝铜矿Cu3(CO3)(2)(OH)(2)在1/3磁化平台上的局部自旋极化，这是畸变金刚石反铁磁自旋1/2链的模型体系。发现Cu2（二聚体）位的超精细场的自旋部分是场无关的、负的和强各向异性的，相当于d轨道中约10%的完全极化自旋。这接近于量子平台的预期配置，其中单重态稳定在二聚体上。然而，观察到的非零自旋极化指向一些三重态混合物，这是由金刚石键J1和J3的强不对称性引起的。
High magnetic field (63,65)Cu NMR spectra were used to determine the local spin polarization in the 1/3 magnetization plateau of azurite, Cu3(CO3)(2)(OH)(2), which is a model system for the distorted diamond antiferromagnetic spin-1/2 chain. The spin part of the hyperfine field of the Cu2 (dimer) sites is found to be field independent, negative and strongly anisotropic, corresponding to approximately 10% of fully polarized spin in a d orbital. This is close to the expected configuration of the quantum plateau, where a singlet state is stabilized on the dimer. However, the observed nonzero spin polarization points to some triplet admixture, induced by strong asymmetry of the diamond bonds J1 and J3.