Magnetic Raman scattering of the ordered tetrahedral spin-1/2 clusters in Cu2Te2O5(Br1-xClx)2 compounds

被引：24

作者：

Jensen, J

Lemmens, P

Gros, C

机构：

[1] Niels Bohr Inst, Osted Lab, DK-2100 Copenhagen, Denmark

[2] Max Planck Inst Solid State Res, D-70569 Stuttgart, Germany

[3] Univ Saarland, Fak 7, D-66041 Saarbrucken, Germany

来源：

EUROPHYSICS LETTERS | 2003年 / 64卷 / 05期

关键词：

D O I：

10.1209/epl/i2003-00281-7

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Raman light-scattering experiments in the antiferromagnetic phase of the Cu2Te2O5(Br1-xClx)(2) compounds are analyzed in terms of a dimerized spin model for the tetrahedral Cu-clusters. It is shown that the longitudinal magnetic excitation in the pure Br system hybridizes with a localized singlet excitation due to the presence of a Dzyaloshinskii-Moriya anisotropy term. The drastic change of the magnetic scattering intensities observed when a proportion of Br is replaced by Cl ions, is proposed to be caused by a change of the magnetic order parameter. Instead of being parallel/antiparallel with each other, the spins in the two pairs of spin-1/2 order perpendicular to each other, when the composition x is larger than about 0.25.

引用

页码：689 / 695

页数：7

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