  Neutron diffraction and small angle scattering experiments have been carried
out on the double-isotopic polycrystalline sample (7Li0.82Fe0.18OD)FeSe.
Profile refinements of the diffraction data establish the composition and
reveal an essentially single phase material with lattice parameters of a=
3.7827 {\AA} and c= 9.1277 {\AA} at 4 K, in the ferromagnetic-superconductor
regime, with a bulk superconducting transition of TC = 18 K. Small angle
neutron scattering (SANS) measurements in zero applied field reveal the onset
of ferromagnetic order below TF ~ 12.5 K, with a wave vector and temperature
dependence consistent with an inhomogeneous ferromagnet of spontaneous vortices
or domains in a mixed state. No oscillatory long range ordered magnetic state
is observed. Field dependent measurements establish a separate component of
magnetic scattering from the vortex lattice, which occurs at the expected wave
vector. The temperature dependence of the vortex scattering does not indicate
any contribution from the ferromagnetism, consistent with diffraction data that
indicate that the ordered ferromagnetic moment is quite small.
