  We show the observation of the coexistence of bulk superconductivity and
ferromagnetism in CeO1-xFxBiS2(x = 0 - 1.0) prepared by annealing under
high-pressure. In CeO1-xFxBiS2 system, both superconductivity and two types of
ferromagnetism with respective magnetic transition temperatures of 4.5 K and
7.5 K are induced upon systematic F substitution. This fact suggests that
carriers generated by the substitution of O by F are supplied to not only the
BiS2 superconducting layers but also the CeO blocking layers. Furthermore, the
highest superconducting transition temperature is observed when the
ferromagnetism is also enhanced, which implies that superconductivity and
ferromagnetism are linked to each other in the CeO1-xFxBiS2 system.
