Neutron Spin-Echo Investigation of Slow Spin Dynamics in Kagome-Bilayer Frustrated Magnets as Evidence for Phonon Assisted Relaxation in SrCr{sub 9x}Ga{sub 12-9x}O{sub 19}

Journal Article · Fri Jul 28 00:00:00 EDT 2006 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.97.047203· OSTI ID:20860581

Mutka, H; Ehlers, G; Stewart, J R; Fouquet, P ^[1]; Payen, C; Mevellec, J Y ^[2]; Bono, D; Mendels, P; Blanchard, N ^[3]; Collin, G ^[4]

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1. Institut Laue-Langevin, Boite Postale 156X, F-38042 Grenoble Cedex 9 (France)
2. Institut des Materiaux Jean Rouxel, UMR 6502, Universite de Nantes, Boite Postale 32229, F-44322 Nantes Cedex 3 (France)
3. Laboratoire de Physique des Solides, UMR 8502, Universite Paris-Sud, 91405 Orsay (France)
4. Laboratoire Leon Brillouin, CE Saclay, CEA-CNRS, 91191 Gif-sur Yvette (France)

A neutron spin-echo investigation of the low temperature spin dynamics in two well-characterized kagome bilayer compounds SrCr{sub 9x}Ga{sub 12-9x}O{sub 19} (x=0.95, SCGO) and Ba{sub 2}Sn{sub 2}ZnCr{sub 7x}Ga{sub 10-7x}O{sub 22} (x=0.97, BSZCGO) reveals two novel features. One is the slowing down of the relaxation rate without critical behavior at T{sub g}, where a macroscopic spin-glass-like freezing occurs. The second is, in SCGO at 4 K ({approx_equal}T{sub g})<T<7 K, the relaxation rate activation energy E{sub a}=7{+-}0.4 meV, equal to the energy of a phonon mode, pointing out the role of spin-lattice coupling.

• OSTI ID: 20860581
• Journal Information: Physical Review Letters, Vol. 97, Issue 4; Other Information: DOI: 10.1103/PhysRevLett.97.047203; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACTIVATION ENERGY
CHROMIUM COMPOUNDS
FREEZING
GALLIUM OXIDES
MAGNETS
NEUTRONS
PHONONS
RELAXATION
SLOWING-DOWN
SPIN
SPIN ECHO
SPIN GLASS STATE
STRONTIUM COMPOUNDS
TEMPERATURE RANGE 0000-0013 K