POLARIZED NEUTRON-SCATTERING FROM THE SURFACE AND BULK OF MAGNETIC FLUID

We have studied the local magnetic properties of a ferrofluid near the surface layer and in the bulk volume, using narrow (similar to 1.5 mm ) polarised neutron beam. The polarisation of the transmitted beam sho wed some peculiarities (found by three-dimensional analysis) near the surface comparing to the bulk region. These peculiarities are better m anifested when a magnetic field is applied and an increased spin rotat ion was observed near the surface. The small angle scattering intensit y near the surface region was higher than in the bulk volume. The q de pendence of surface section reveals clusters with a spread of size app roximate to 10(2)-10(3) Angstrom, which can be connected with a low fr actal dimensionality D-f congruent to 1. In bulk material the nuclear- magnetic interference cross-section measured corresponds to the theore tical prediction.