INVESTIGADORES
KAUL Enrique Eduardo
artículos
Título:
Evidence for an Unconventional Magnetic Instability in the Spin-Tetrahedra System Cu2Te2O5Br2
Autor/es:
P. LEMMENS; K.-Y. CHOI; E. E. KAUL; C. GEIBEL; K. BECKER; W. BRENIG; R. VALENTI; C. GROS; M. JOHNSSON; P. MILLET; F. MILA
Revista:
PHYSICAL REVIEW LETTERS
Editorial:
The American Physical Society
Referencias:
Año: 2001 vol. 87 p. 2272011 - 2272014
ISSN:
0031-9007
Resumen:
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 TN = 18.2 K is consistent with 3D antiferromagnetic ordering, the phase transition at To = 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.
