  Polarized neutron diffraction allows to determine the local susceptibility
tensor on the magnetic site both in single crystals and powders. It is widely
used in the studies of single crystals, but it is still hardly applicable to a
number of highly interesting powder materials, like molecular magnets or
nanoscale systems because of the low luminosity of existing instruments and the
absence of an appropriate data analysis software. We show that these
difficulties can be overcome by using a large area detector in combination with
the two-dimensional Rietveld method and powder samples with magnetically
induced preferred crystallite orientation. This is demonstrated by revisiting
two test powder compounds, namely, low anisotropy (soft) ferrimagnetic compound
Fe3O4 and spin-ice compound Ho2Ti2O7 with high local anisotropy. The values of
magnetic moments in Fe3O4 and the susceptibility tensors of Ho2Ti2O7 at various
temperatures and fields were found in perfect agreement with these found
earlier in single crystal experiments. The magnetically induced preferred
crystallite orientation was used to study the local susceptibility of a
single-molecule magnet Co([(CH3)2N]2CS)2Cl2. Hence, the studies of local
magnetic anisotropy in powder systems might now become accessible.
