Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
Phys Rev Lett. 2012 May 4;108(18):187206. doi: 10.1103/PhysRevLett.108.187206. Epub 2012 May 3.
A quantum magnet, LiCuSbO4, with chains of edge-sharing spin-1/2 CuO6 octahedra is reported. While short-range order is observed for T<10 K, no zero-field phase transition or spin freezing occurs down to 100 mK. Specific heat indicates a distinct high-field phase near the 12 T saturation field. Neutron scattering shows incommensurate spin correlations with q=(0.47±0.01)π/a and places an upper limit of 70 μeV on any spin gap. Exact diagonalization of 16-spin easy-plane spin-1/2 chains with competing ferro- and antiferromagnetic interactions (J1=-75 K, J2=34 K) accounts for the T>2 K data.
报道了一种具有链状边缘共享自旋-1/2 CuO6 八面体的量子磁体 LiCuSbO4。尽管在 T<10 K 时观察到短程有序，但在 100 mK 以下没有零场相变或自旋冻结。比热表明在 12 T 饱和场附近存在明显的高场相。中子散射显示出具有 q=(0.47±0.01)π/a 的不相干自旋相关，并对任何自旋能隙施加了 70 μeV 的上限。用竞争的铁磁和反铁磁相互作用（J1=-75 K，J2=34 K）对 16 自旋易面自旋-1/2 链进行精确对角化，解释了 T>2 K 的数据。
