Magnetic ordering and spin excitations in the frustrated magnet MnSc2S4 -: art. no. 014413

The A-site spinel compound MnSc2S4 exhibits strong frustration effects with a low ordering temperature (T-N=2.3 K). Detailed neutron-scattering investigations have been performed to study the magnetic ordering process and the associated magnetic excitations. The magnetic structure found at T=1.5 K is a spiral within the a-b plane characterized by a propagation vector of q=(3/4,3/4,0). The magnetic ordering process is spectroscopically reflected by a change from a purely quasielastic to an inelastic response. The quasielastic line width corresponds to a magnetic energy scale of approximate to 1 meV which is consistent with the spin wave stiffness as determined from the magnon dispersion at low temperatures.