Magnetic excitations and quantum fluctuation in the covalent-chain antiferromagnet TlFeS2
Hahn-Meitner-Institut - Postfach 390128, D-14091 Berlin, Germany
2 Rutherford Appleton Laboratory - Chilton, Didcot, Oxfordshire, UK
Accepted: 14 March 1996
Magnetic excitations in the covalent-chain antiferromagnet with a low ordered spin were studied by time-of-flight neutron scattering. The scattering intensities are in agreement with a non-interacting multi-magnon model for intrinsic spins and a zero-point quantum reduction , confirming the predicted from the spin-wave energy dispersion. No evidence is found for charge fluctuation on the spin-wave energy scale. A local-moment Heisenberg Hamiltonian and conventional harmonic spin-wave theory thus apply to Néel-ordered , where the two-magnon signal allows to determine the unknown local spin S.
PACS: 75.10.Jm – Quantized spin models / 75.30.-m – Magnetically ordered materials: other intrinsic properties / 75.50.Ee – Antiferromagnetics
© EDP Sciences, 1996