Ferro-antiferromagnetic delta-chain system studied by high field magnetization measurements
Ferro-antiferromagnetic delta-chain system studied by high field magnetization measurements
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DOI：
10.1143/jpsj.74.2831
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发表时间：
2005-10-01
影响因子：
1.7
通讯作者：
Tonegawa, T
中科院分区：
文献类型：
--
作者：
Inagaki, Y;Narumi, Y;Tonegawa, T
测量了S=1/2铁-反铁磁三角链体系[Cu(Bpy)(H2O)][Cu(Bpy)(Mal)-(H2O)](ClO4)(2)的高场磁化过程。在低温下，观测到的磁化曲线显示在约1T以下迅速增加到饱和磁矩的一半，然后逐渐增加到低于约7T的全极化状态。关于这一特征的磁化过程，我们定性地讨论了基于非相互作用的两亚晶格模型的体系的圆态，其中三角链被分成顶端自由自旋和剩余的基自旋，被认为是准一维反铁磁链。通过与无相互作用双子晶格模型的理论曲线和数值计算曲线的比较，指出了连接顶端自旋和基态自旋的铁磁相互作用的本质作用。基于自旋波理论的饱和行为和/或饱和场本身的论证也表明了Dzyaloshinskii-Moriya相互作用的存在。
High field magnetization processes were measured for the single crystal of an S = 1/2 ferro-antiferromagnetic delta-chain system [Cu(bpy)(H2O)][Cu(bpy)(mal)-(H2O)](ClO4)(2). At low temperatures, the observed magnetization curve shows a rapid increase to half of the saturation moment below about I T and then followed by a gradual increase to fully polarized state below about 7 T. Concerning this characteristic magnetization process, we discuss the round state of the system qualitatively based oil a non-interacting two sublattice model, where a delta-chain is divided into apical free spins and remaining basal spins regarded as quasi one dimensional antiferromagnetic chain. Essential effect of ferromagnetic interaction, which connects an apical spin and basal spins, is pointed out from the comparison with theoretical curve for the non-interacting two sublattice model as well as with the numerically calculated curve. Presence of the Dzyaloshinskii-Moriya interaction is also suggested from the arguments for the saturation behavior and/or saturation field itself based on the spin wave theory.