Polarized small-angle neutron scattering (SANSPOL) for discrimination of nanosized components in ferrofluids

A. Heinemann - A. Wiedenmann - M. Kammel - A. Hoell

Hahn-Meitner-Institut Berlin, Glienicker Straße 100, D-14109 Berlin, Germany

Abstract
The use of polarized neutron technique in small-angle scattering (SANS) have led to new results in the case of magnetic nanometer-scale structure analysis. Different magnetic cross sections for spin-up and spin-down neutron scattering can be combined with chemical contrast variation methods. We show that the analysis of the interference term of nuclear and magnetic scattering respectively enables the extraction of additional information on the composition and magnetization profiles of the samples. This technique profits by the clear distinction between the magnetic and nonmagnetic scattering contributions and the strong auxiliary conditions for model fitting procedures. Beside general formulas for some special cases of present experimental interest, we apply the approach to cobalt based ferrofluid scattering data obtained in the HMI-V4 experiment. Tables 2, Figs 2, Refs 7.