  We have analyzed magnetic-field-dependent small-angle neutron scattering
(SANS) data of soft magnetic two-phase nanocomposite ferromagnets in terms of a
recent micromagnetic theory for the magnetic SANS cross section [D. Honecker
and A. Michels, Phys. Rev. B $\mathbf{87}$, 224426 (2013)]. The approach yields
a value for the average exchange-stiffness constant and provides the Fourier
coefficients of the magnetic anisotropy field and magnetostatic field, which is
related to jumps of the magnetization at internal interfaces.
