Low-energy spin-wave excitations in the bilayer manganite La{sub 1.2}Sr{sub 1.8}Mn{sub 2}O{sub 7}
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
- NIST Center for Neutron Research, National Institute for Standards and Technology, Gaithersburg, Maryland 20899 (United States)
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
Inelastic neutron scattering experiments were performed on a single crystal of the bilayer manganite La{sub 1.2}Sr{sub 1.8}Mn{sub 2}O{sub 7}. Low-energy spin-wave excitations were observed along the c direction with a maximum energy of {approx} 0.5 meV at the zone boundary. The dispersion of these acoustic spin wave modes is modeled by a nearest-neighbor Heisenberg model with an interbilayer exchange interaction between neighboring spins in different bilayers of 0.048(1) meV and an anisotropy gap of {delta} 0.077(3) meV. These results confirm the two-dimensional nature of the spin correlations in the bilayer manganites, with a ratio of the in-plane to interbilayer interaction of {approx} 200. The temperature dependence of the energies and intensities of the spin wave excitations are in agreement with our earlier conclusion that the ferromagnetic transition is second order. (c) 2000 American Institute of Physics.
- OSTI ID:
- 20216250
- Journal Information:
- Journal of Applied Physics, Vol. 87, Issue 9; Other Information: PBD: 1 May 2000; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
Spin correlations of the magnetoresistive bilayer manganite La{sub 1.2}Sr{sub 1.8}Mn{sub 2}O{sub 7}
Magnetic correlations in the bilayer manganite La{sub 1.2}Sr{sub 1.8}Mn{sub 2}O{sub 7}