Li2VO(Si, Ge)O4, a prototype of a two-dimensional frustrated quantum Heisenberg antiferromagnet
Li2VO(Si, Ge)O4, a prototype of a two-dimensional frustrated quantum Heisenberg antiferromagnet
复制标题
DOI：
10.1103/physrevlett.85.1318
复制
发表时间：
2000-08-07
影响因子：
8.6
通讯作者：
Mila, F
中科院分区：
文献类型：
--
作者：
Melzi, R;Carretta, P;Mila, F
报道了Li_2VOSiO_4和LiVOGcO（4）的核磁共振和磁化强度的测量结果。磁化率的分析表明，这两种化合物都是二维的S = 1/2海森堡反铁磁体，正方形晶格上的超交换耦合J（1）沿着正方形的边和J（2）沿着对角线的竞争引起了相当大的阻挫.当J（2）/J（1）> 0.5时，Li 2 VOSiO 4的低温相变为共线相变。就在磁性转变的上方，两个共线基态之间的简并度被结构畸变的发生所提升。
NMR and magnetization measurements in Li2VOSiO4 and LiVOGcO(4) are reported. The analysis of the susceptibility shows that both compounds are two-dimensional S = 1/2 Heisenberg antiferromagnets on a square lattice with a sizable frustration induced by the competition between the superxchange couplings J(1) along the sides of the square and J(2) along the diagonal. Li2VOSiO4 undergoes a low-temperature phase transition to a collinear order, as theoretically predicted for J(2)/J(1) > 0.5. Just above the magnetic transition the degeneracy between the two collinear ground states is lifted by the onset of a structural distortion.