Evidence for an unconventional magnetic instability in the spin-tetrahedra system Cu2Te2O5Br2 -: art. no. 227201

被引：74

作者：

Lemmens, P ^{[1
]}

Choi, KY

Kaul, EE

Geibel, C

Becker, K

Brenig, W

Valenti, R

Gros, C

Johnsson, M

Millet, P

Mila, F

机构：

[1] Rhein Westfal TH Aachen, Inst Phys 2, D-56056 Aachen, Germany

[2] Max Planck Inst Chem Phys Stoffe, D-01187 Dresden, Germany

[3] Tech Univ Dresden, Inst Theoret Phys, D-01069 Dresden, Germany

[4] Univ Saarland, Inst Theoret Phys, D-66041 Saarbrucken, Germany

[5] Univ Stockholm, Dept Inorgan Chem, S-10691 Stockholm, Sweden

[6] CNRS, Ctr Elaborat Mat & Etud Struct, F-31062 Toulouse, France

[7] Univ Lausanne, Inst Phys Theor, CH-1015 Lausanne, Switzerland

[8] Tech Univ Braunschweig, Inst Theoret Phys, D-3300 Braunschweig, Germany

来源：

PHYSICAL REVIEW LETTERS | 2001年 / 87卷 / 22期

关键词：

D O I：

10.1103/PhysRevLett.87.227201

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Thermodynamic experiments as well as Raman scattering have been used to study the magnetic instabilities in the spin-tetrahedra systems Cu2Te2O5X2, X = Cl and Br. While the phase transition observed in the Cl system at T-N = 18.2 K is consistent with 3D antiferromagnetic ordering, the phase transition at T-o = 11.4 K in the Br system has several unusual features. We propose an explanation in terms of weakly coupled tetrahedra with a singlet-triplet gap and low-lying singlets.

引用

页码：227201 / 227201

页数：4

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