Abstract
Bulk magnetization, transport and neutron scattering measurements were performed to investigate
the electronic and magnetic properties of a polycrystalline sample of the newly discovered
ferromagnetic superconductor, CeO0:3F0:7BiS2. Ferromagnetism develops below TFM = 6.54(8) K
and superconductivity is found to coexist with the ferromagnetic state below TSC 4.5 K. Inelastic
neutron scattering measurements reveal a very weakly dispersive magnetic excitation at 1.8 meV
that can be explained by an Ising-like spin Hamiltonian. Under application of an external magnetic
eld, the direction of the magnetic moment changes from the c-axis to the ab-plane and the 1.8
meV excitation splits into two modes. A possible mechanism for the unusual magnetism and its
relation to superconductivity is discussed.
