INTERACTION EFFECTS IN NON-POLAR AND POLAR FERROFLUIDS BY SMALL-ANGLE NEUTRON SCATTERING

摘要

Small-angle scattering of non-polarized neutrons is applied to reveal the character of the interparticle interaction in ferrofluids. Scattering curves obtained at the SANS diffractometer of the Budapest Neutron Center are analyzed with respect to the scattering structure-factor reflecting this interaction. Two types of ferrofluids which are magnetite stabilized sterically in non-polar (benzene) and polar (pentanol) carriers, are considered. A principle difference between the two types of non-magnetized samples is observed. In the non-polar fluids the interaction effect on the scattering is small even for a comparatively high volume fraction of magnetite ( > 5 %), while in polar fluids it starts to be visible since 1%, which can be explained by the observed difference in the characters of the interaction potential.