Magnetic excitations of superconducting LaFeAsO0.89F0.11

For a polycrystalline sample of the superconducting LaFeAsO1-xFx(x∼0.11), neutron inelastic magnetic scattering peaks have been observed by the scans of the absolute scattering vector Q at various fixed transfer energies E. Their Q positions (∼1.1 A-1) corresponds to the (π,0) point in the reciprocal space. The E and temperature (T) dependencies of their integrated intensities and the T dependence of the peak widths do not have such significant characteristics as can be considered as the evidence for the resonance peak expected for the so-called s± symmetry of the superconducting order parameter.