Incommensurate magnetism in the coupled spin tetrahedra system Cu₂Te₂O₅Cl₂
Neutron scattering studies on powder and single crystals have provided new evidences for unconventional magnetism in Cu₂Te₂O₅Cl₂. The compound is built from tetrahedral clusters of S = 1/2 Cu²⁺ spins located on a tetragonal lattice. Magnetic ordering, emerging at TN = 18.2 K, leads to a very comp...
Збережено в:
| Дата: | 2005 |
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| Автори: | , , , , , , , |
| Формат: | Стаття |
| Мова: | English |
| Опубліковано: |
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
2005
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| Назва видання: | Физика низких температур |
| Теми: | |
| Онлайн доступ: | http://dspace.nbuv.gov.ua/handle/123456789/121701 |
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| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | Incommensurate magnetism in the coupled spin tetrahedra system Cu₂Te₂O₅Cl₂ / O. Zaharko, H.M. Ronnow, A. Daoud-Aladine, S. Streule, F. Juranyi, J. Mesot, H. Berger, P.J. Brown // Физика низких температур. — 2005. — Т. 31, № 8-9. — С. 1068-1072. — Бібліогр.: 17 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| Резюме: | Neutron scattering studies on powder and single crystals have provided new evidences for unconventional
magnetism in Cu₂Te₂O₅Cl₂. The compound is built from tetrahedral clusters of S = 1/2
Cu²⁺ spins located on a tetragonal lattice. Magnetic ordering, emerging at TN = 18.2 K, leads to a
very complex multi-domain, most likely degenerate, ground state, which is characterized by an incommensurate
(ICM) wave vector k ~ [0.15, 0.42, 1/2]. The Cu²⁺ ions carry a magnetic moment
of 0.67(1) μB/Cu²⁺ at 1.5 K and form a four helices spin arrangement with two canted pairs
within the tetrahedra. A domain redistribution is observed when a magnetic field is applied in the
tetragonal plane (Hc ≈ 0.5 T), but not for H||c up to 4 T. The excitation spectrum is characterized
by two well-defined modes, one completely dispersionless at 6 meV, the other strongly dispersing
to a gap of 2 meV. The reason for such complex ground state and spin excitations may be geometrical
frustration of the Cu²⁺ spins within the tetrahedra, intra- and inter-tetrahedral couplings having
similar strengths and strong Dzyaloshinski–Moriya anisotropy. Candidates for the dominant
intra- and inter-tetrahedral interactions are proposed. |
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