Polarized neutron channeling as a tool for the investigations of weakly magnetic thin films
S. V. Kozhevnikov+*, Yu. N. Khaydukov×°, T. Keller×°, F. Ott*, F. Radu∇
+Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 141980 Dubna, Russia
*Laboratoire Léon Brillouin UMR12 CEA/CNRS, F-91191 Gif sur Yvette, France
×Max-Planck-Institut für Festkörperforschung, D-70569 Stuttgart, Germany
°Max Planck Society Outstation at FRM-II, D-85747 Garching, Germany
∇Helmholtz-Zentrum Berlin für Materialien und Energie, D-12489 Berlin, Germany
We present and apply a new method to measure directly weak
magnetization in thin films.
The polarization of a neutron beam channeling through a thin film
structure is measured after
exiting the structure edge as a microbeam. We have applied the method
to a tri-layer thin film
structure acting as a planar waveguide for polarized neutrons.
The middle guiding layer is a rare
earth based ferrimagnetic material TbCo5 with a low magnetization
of about 20 mT. We
demonstrate that the channeling method is more sensitive
than the specular neutron reflection method.